I think it’s the other way around - you can’t look at the four of them individually, sum them up, and say, “therefore, the Beatles really weren’t all that great.” That argument won’t fly.
Bands are collaborations of musicians, and people working with each other, bouncing ideas off one another, are usually a lot better than the same people would be working by themselves.
It’s true even with bands with dominant frontmen: take The Police, versus Sting as a solo artist. Whatever Andy Summers and Stewart Copeland contributed (and I’m not denigrating them here; I just don’t know enough about music to understand, let alone evaluate, their contribution), they made Sting as frontman of The Police a hell of a lot better than Sting ever was by himself.