The best scenario is avoiding the Great War and you have plenty of places to set in motion its butterfly but then it is rather daunting imagining a world without the World Wars. The next best scenario is a Central powers victory or even stalemated Great War, messier but still likely to leave German borders intact.
In this world one might never see Communism or Fascism emerge, although I think both the left and right might still breed some dangerous actors and one might still see revolution and reactionary governments come to power, especially as decolonialization takes on momentum.
For one I see the British Empire holding its place as the only global power here and acting as world policeman far longer, it will likely be torn asunder in the brush fire wars. The RN remains premier and the FAA likely develop into a more potent strike force, the Army devolves to fight on the fringes and if the RAF emerges it is focused on air defense and bombers until the SLBM fades its role to self-defense. London remains the prime global finance center but it is dogged closely by New York and slightly more distantly by the banking rivals in Germany. The UK evolves a niche focused and boutique manufacturing sector that might do better in the post-industrial era but it likely still loses big in mass market sectors to American and German and later Japanese and Chinese competitors.
France will eventually face its twilight as a great power and likely go bankrupt fighting to hold its colonial empire. Biggest danger will be either Japan or more likely China supporting independence in Indochina with both Germany and the USA earning more sway in its other holdings as they both buy materials and export products. It will eventually see itself integrated into the continental trade links. It likely forms good bonds with Italy and Greece, makes inroads in Romania and becomes a strong exporter to Russia, benefitting from being its biggest creditor, but as debts climb and Russia stagnates that relationship may upend France yet again. It looks rather akin to how Canada is to the USA.
Russia likely sees itself fall into a trap of exporting raw materials, later especially oil and gas, as well as food and cheap manufacturers rather than actually transition to stronger economic underpinnings. Maybe revolution but I think it gets just wealthy enough to limp along. It is the biggest threat to start a regional war with the Ottomans, the Chinese or the Japanese, but it may see high tension with Germany for quite some time. In some ways it looks like Mexico does with respect to the USA, a place to outsource the dirty industry. It might face some real pressure from the Poles to grant independence, Germany has a dog in that hunt and German Poles might urge Germany to get reckless, it may be quite the flashpoint.
A-H will face its share of challenges but I do not feel it shatters, likely it simply crumbles and goes through an ugly divorce. As always it is this region that fuels the greatest risk of war, the Germans cannot have any genuine enemies on its underbelly so it must intervene, the other powers have plenty of notions about getting involved, but it might simply look rather like modern Europe, a bunch of new states enjoying independence but swimming up river in a global economy truly dominated by a few. At best I think it splits, Hungary goes its own way, Austria might hold some non-Germans but I think it loses enough.
Italy stays on the long vacation, although it as many ambitions, it will slowly lose its relevance and fade into being the biggest player in the Med until someone else arrives. Eventually it might capitalize on Libyan oil and gas to develop a rather breezy and sunny economy, a great place to visit or retire to.
The USA still emerges as a global economic power but not as hegemonic. It likely zeniths as a great naval power by the end of the 1940s as events in Asia diffuse its fears. As a country it might look far more regionalized, have more ethnic diversity among the "white" population and see racism linger longer and have more potential to shatter its inner workings than we suspect. Americans run around the world chasing business opportunity and challenging the British hegemony as perceived to be counter to its interests and values, but it may never see itself as a military power.
The Ottomans likely fade to almost extinction, the biggest threats being the British and Russians, but once the oil begins to flow and any authority remains in the Empire then it will have a new day in the sun. We will still see some violence on the Arabian peninsula, the Empire will certainly reassert itself and the British will not be happy, but German interest might be enough to dissuade the British from going to war. On a positive note there should be no Armenian genocide and less pressure to cleanse the Greeks, this Empire might have some better diversity and all the wealth might actually uplift the entire region, its peoples should pass into modernity with ties to Europe that hopefully solidify long term peace. The biggest danger might be a war sparked off by the Greeks or Bulgarians as the Ottomans fall the weakest, assuming the Russians do not pounce first.
Japan likely still goes on to grab the power in Asia but its hands are far more tied with the European powers firmly entrenched. If it can avoid an open war, likely enough, it may become a major trade partner with the British and quietly undermine the Empire's grasp to open markets. It likely develops into a significant regional power but forever in the shadow of China. Worst case scenario it goes militaristic and stagnates into a rather poor facsimile of the USSR.
China likely struggles even longer to shake off the influence of the West and reassert its independence, it likely remains poor and like modern China leverages its huge pool of cheap labor to industrialize and accrue wealth. It may indeed become one of the biggest players in Asia but built on the backs of its people with even more pressure from below as the wealth divide will not be masked by the Communist façade. We might see something like communism emerge here to redress the grinding poverty that was China's history.
And of course the Reich, it might be one of those places that actually breaks under the Kaiser and goes into revolt, but more likely I see it transitioning towards a limited monarch and more socialist leaning democracy with oddly strong doses of Liberal strains, this should be the number two power, third economically, compared to the British Empire or the USA but decidedly the continental juggernaut. It should remain equal to Russia in real power despite less population, maybe a bit behind in GDP but per capita GDP will tell us the Germans have real wealth in depth. Likely a world leader in many industries and a stronger competitor in many more, if it is made from metal or manufactured for precision or efficiency then it comes from Germany. If the Empire fails then it goes to the Germans versus the USA for dominance globally. Germany likely lives with a strong fear of Russian ambitions and faces a lot of potential unrest all around it so it may remain a strong military power long after others let their militaries fade. I can see German peacekeepers, advisors and operatives perennially deployed as Germany wades into the sort of messes the USA did in OTL. The might prop up the Dutch in DEI, or the South Africans or even the French in Indochina, or they might champion China versus Japan or woo Japan by supporting gambits into China and showdowns with the other Europeans by proxy. Germany will be a quixotic figure, too much like how the USA got sucked into vacuums left as other powers faded or were pushed from the board, yet never quite so dominant.
This multilateral world will be both more dangerous and less fragmentary than our own, Europe will hold sway longer, its culture, language and influence will set more deeply in places like Africa, one might see more but less fearsome wars, more violence in the shadows, but also more peace and a different distribution of wealth, it could be very different or almost the same.