Here's my two cents - No George, no Beatles:
1) In the beginning, it was George's rockabilly guitar that really made the Beatles stand out. Think 1959, 1960, between the time of The Casbah/other Liverpool coffee houses, and maybe their first paying gigs. No Lennon-McCartney originals back then, and the harmonies were still being worked out. But George could play guitar really well, that tune Raunchy isn't that easy, and he was doing Carl Perkins from the beginnign. Even as late as the Star Club tapes, George's guitar was front and center, and really was as much the Beatles sound as anything else. Without George's sound to lean on, would John and Paul have gotten gigs in the early days?
2) Though it was the John-Paul harmonies that seemed to stand out in the early and mid-Beatlemania days (From Me to You, I want to Hold Your Hand, etc.), I think the essence of their singing was THREE-part harmony, going way back to their learning "To Know Him is to Love Him" by the Teddy Bears. Three guys singing front and center into two mics - not just the visuals, but the sound must have made them stand out head and shoulders above the other Liverpool groups. No George ... would they have learned to sing as well? And if they didn't would they have turned into the Beatles?
Well, reading all this, maybe it's not even worth my two cents, but I'll throw at least one in!