I think he easily casted the widest net. He has such a great ear/intuition/whatever you may call it for pop songwriting. Where Ringo was great at drums, but couldn't really crack through nearly as much in other departments, and George where his Beatles work represents some of my favorite material that they produced and I would argue he had the best "batting average" in the band, maybe he just couldn't generate enough volume to make great records on his own. John had the tools, but could be a little alienating. Paul just checks all the boxes.
The cool thing about the Beatles as a unit though is that they truly were greater than the sum of their parts. I would say much, much greater. John has some great solo stuff but it feels patchy to me, Paul has a couple of really good records and some scattered tracks, George never really resonated with me past the Beatles and neither did Ringo, but together... Man, those are some of the best songs and records of all time.