Ah, guys, I'm not sure but what you miss the point.
Maybe it takes someone who actually lived through the era, but MacDonalds was a paradigm breaking business. In retrospect, you can say 'sure it was inevitable', but I'm not at all sure it was.
I grew up in Saskatoon, SK in the 60's and 70's. Before MacDonalds there was NOTHING like it. Yes, there were lots of drive in burger joints - but the only one that made a profit and stayed in business was A&W, and it was very much the 'car hop' kind of drive in. Cars full of teens (boys in one car, girls in another) would drive around the parking lot yelling at each other as a weird dating ritual (this was my older brother's cohort, when I was a pre-teen, so all dating rituals looked wierd at the time, but even so...) Grandpa, when he came to town would take us out for a treat. This was NOT A MACDONALDS family friendly sit-down fast food restaurant.
Also, all (I think) the drive-ins closed down all winter.
Yes, KFC existed. Yes, Fish and Chip joints existed. In both cases, they were almost all takeout.
Saskatoon, population 150,000 or so at the time was considered JUST large enough for ONE MacDonalds.
Today's A&W's and KFC's are VERY different from what they were back then, as a direct result of MacDonalds.
IIRC, Burger King and Wendy's at least, grew into what they are today by borrowing large chunks of the Kroc's business model.