It's intriguing to speculate on how the Beatles might have fared in the fractured, arena-rock age of the '70s.
IMHO, they would have maintained their popularity, but lost their position as cultural trendsetters.
If the Beatles never break up, and no members release those solo albums
Even if the Beatles hadn't broken up when they did -- let's say they broke up in 1980 -- there would have been solo albums. Either that, or Harrison would have quit the band completely.
Also the Beatles are unique in that they had two superduperstar frontmen. So even in the best of circumstances -- Brian Epstein lives, no Klein, no Yoko -- there would have been ego clashes between Lennon and McCartney. I can't see a scenario where at least one of them doesn't release solo albums.
Do you think they would've added a Billy Preston or a Jeff Lynne to the band?
No they would not have been willing to split the money
the best post-Beatles album
That would be Plastic Ono Band