*Clears throat* *Straightens tie*
Firstly, keep in mind to avoid hit-the-mark alternate history here. That is a term I use for anything where things exist despite the POD. So if you have it here, Magical Mystery Tour, the White Album, Yellow Submarine, Let it Be, etc all come about exactly the same, just with Brian Epstein around. That isn't how things really work. To paraphrase Doc Brown from Back to the Future III, the future is what you make it and isn't written down. So, from 1967 on, you're making the future. When HTMAH is appropriately acceptable is when it's recognized as what it is, but just used for arguments sake since nothing is sure yet in the discussion, or somethings can never be known for sure. So we can discuss the White Album, Yoko, et al, while keeping in mind the likelihood of butterflies in reality.
Onto the discussion proper:
Brian Epstein is generally seen as the Christ figure for the Beatles, which is odd since he's Jewish, who would have calmed every conflict and wiped away every tear. That's a fair assessment in my opinion, with some quibbles since it won't all be perfect.
Epstein's death was the beginning of the end for the band. It sunk Lennon into doubt and confusion with what he wanted to do with himself and what he was doing, which he had already been going through somewhat since 1966 at least (hence why Paul got his project with "Sgt. Pepper"). That in turn allowed Paul McCartney to step up to greater prominence, which he did because he wanted to rally the band and keep them going after Brian Epstein's death. You can argue whether or not the Beatles would have continued had Paul not done that, or whether they would have drifted apart lazily and ended. The problem with that being that Paul could be bossy, and on the whole the other three increasingly felt like Paul was trying to make it his band. That created tension and resentment. Paul would also do things like record songs all by himself without the others (since he could play multiple instruments), which John Lennon absolutely hated. There's a story, and I can't recall which song it was, but it was one for the White Album, and Lennon and Ringo walked into the room while McCartney was conducting the orchestra or whatever it was to put the final touches on a song he had done all by himself, and it was said you could cut the tension in that room with a knife. To be honest, some of that was certainly Lennon's fault. When he was addicted to heroine (on and off though it may have been) during the 'Get Back' sessions, how can you be shocked and offended when McCartney steps up to take the reigns?
Those two things, being Lennon not being sure and sinking into whatever problem it was and McCartney stepping up to fill a greater role because John was taking a lesser role than before, and cheer leading to keep the group going after Epstein's death out of fear they would end if he wasn't doing his part to push, are what I would say are the two underlying things that ended the Beatles. You also have the fact that the Beatles developed as individuals, and when they grew up they grew apart. But hell, how many artists is that true of who found a way to stay together, or reunited later (which the Beatles would have for want of a nut)? I don't buy that that meant the Beatles had to breakup. Record the occasional solo album on the side, maybe, but not break up.
There are certainly other major issues that came up after Epstein's death which he could have dealt with, or that would not have come up had he lived, and they played a large role in ending the group. George Harrison matured as an artist, which complicated the dynamic since it was previously John and Paul at the front with George and Ringo in the back, and was constantly being denied the chance for the group to release his songs due to Lennon/McCartney veto, and Lennon and McCartney having more interest in their songs than Harrison's. That created a feeling of being kept down, and I do believe it made him upset. You also had Lennon divorce his first wife and marry Yoko Ono, who he subsequently brought into the studio and forced on the band. You had Apple turn into a nightmare since the Beatles had no idea how to run a business, which threatened to bankrupt the Beatles. You had Lennon addicted to heroine for a period. You had the Beatles get taken in by hucksters, like Magic Alex, who conned them out of money. And you had Allen Klein. You also had the Beatles start to squabble more. You also had them grow apart; it got increasingly to a point where, rather than collaboration, it was all too often just one of the members who had completed everything but just needed the rest as a backing group.
Had Epstein lived, you would have ironed out those details and problems. Some may have remained, but they may easily have been lessened, and whatever the case, the group would only be healthier with Brian Epstein. Epstein would have been re-signed had he lived, which I would posit would have alleviated his worries and made him less dependent on his various, hazardous forms of 'escapism' (which ended his life). Lennon, though still unsure of things and a bit removed in the wake of that Beatles apex of 1966, would also have been in higher spirits, not resigned to the idea of "We've fuckin' had it now", and he may well have pulled himself out of his funk. McCartney would also not push things to keep going and be the cheerleader as there would not be the trauma of Epstein's death and lack of overall leadership. That means he doesn't end up being bossy, nor do the Beatles feel like he's trying to be leader and runner of the group. 'Sgt. Pepper's Lonely Hearts Club Band' was a first which became a norm, being it was an idea Paul McCartney had for an album to do which the others went along with and did their bit for and theirs songs for. It then went on to be a norm, since Paul came up with the idea of doing the albums 'Magical Mystery Tour' and 'Get Back/Let it Be', and I think he did have the initial inkling for what became 'Abbey Road' in the wake of the failure of the 'Get Back' sessions (not the album itself, but the getting back to getting back to George Martin). Had Epstein lived, taking into account that alternate dynamic where Lennon isn't so removed and McCartney doesn't step up to fill voids, there's a good chance for that to not be so much the case.
All that dynamic in turn would also prevent or lessen any tensions, and you'd have Epstein there to manage and work things out. On the whole, so many of the Beatles problems came from being a force unmanaged. And none of the Beatles could be the ones to manage it, as we saw, because it only lead to imbalance and growing conflict.
Epstein would also have been able to manage Apple better. That's probably where he'd find himself dedicated most in the wake of the Beatles no longer touring. With Apple having business sense and proper (enough) management, it would avoid becoming the out of control thing it became. The exact details of that, don't ask me. Epstein would also probably manage to beat off con men and keep them away from the band. And certainly there'll be no need for Allen Klein, which only bodes well.
The issue of George Harrison growing as an artists is a bit of a tough one. I think Epstein would have recognized it as an issue: something that could introduce instability into the balance of the group, and which would make George unhappy as he wanted to do his thing but was being denied, which in turn would also introduce tension. I don't know if Epstein would do it, but if I were in his shoes, I would have George Harrison release a solo album sometime past 1968 in order to release built up pressure, and potentially increase the allotment of Harrison songs per album to a higher number. The reason I don't know if he'd do it is that Epstein seems to me, based on what I know, to want to group to remain as 'what it is' as possible. His trepidation over 'Sgt Pepper's' is my example for that. What a George Harrison album would potentially say, or what he could be afraid it would say, is that the Beatles aren't unified. But what the hell else can you do? Maybe you could manage it by just getting Lennon and McCartney to give George more space on the albums and singles instead. Something needs to be done, though.
Yoko Ono would probably be a bit of an issue with Epstein, because you're running against Lennon's stubbornness. Lennon's heroine problem (assuming it arises) would potentially be in the same boat. I don't see a way Epstein doesn't recognize Ono being brought into the studio as a destabilizing element and a source for tension. So he will want that not to happen. How he makes that not happen is the problem. If he talks to Lennon, it will probably fall on deaf ears with Lennon telling him off. I will say that if he doesn't manage to stop that, you've already removed so many problems in this scenario that Yoko won't be all that bad. If Lennon get's addicted to heroine, Epstein will recognize that as a problem since it will make Lennon incapacitated as an artist and meandering as an artist. I don't know what he would do to stop it, but he'd try something.
(Train of thought lost)
If you want the overall vibe: there's a lot of things that could have been different and are variable as is, but the whole mechanics of the Beatles existence were that they needed an impartial friend to oversee them and oversee and iron out the details and keep things in order. When they lost that is when the problems arrived. McCartney wanted to keep things going, but he only made the others feel he wanted to be the boss (true or not) and they wanted to be 'The Beatles' not a Paul McCartney band. A member could not fill the void in any way left by the loss of a good management. The Beatles were a force which was governed previously, but lost that governance and became increasingly unstable and chaotic and a result, with problems and imperfections too much unresolved and unfixed and only building up. That force eventually, in its instability, exploded and flew apart, occasionally coalescing in parts but never permanently, and never coalescing back into a whole. Were Epstein alive, that force would remained governed, not perfectly but better than what things turned out to be, and it would remain comparatively much more stable and balanced.
