I think Paul uses just about anything that works!
I don't understand the nostalgia for old amp sounds and recording techniques either (the fabricated vintage sound of The Strokes debut drove me mad at the time, who wants muffled and distorted vocals?)
Interesting point!
My band plays (played?) psychedelic rock. There are endless nouveau psychedelic bands that go to a lot of effort to sound like garage rock recordings from the '60s. Vocals sent too hot to tape and then bathed in tape echo, drums clattering away as captured with a single overhead, bass a distant rumble, etc. It all sounds the same. My bandmates collect these sampler vinyl records from obscure indie labels and it is all songs from "The X" and "The Y", and it all sounds the same. Skinny guys dressed up like extras from Easy Rider making music that sounds like it was rejected from the Nuggets compilations. The game, really, is just to find "The Z"band and follow them on Instagram before any of the rest of us do it, then pretend to be a lifelong fan. Musical Top Trumps.
My band, to our credit, have taken a different approach. We record with technical prog metal guys who capture everything as carefully as possible. They will happily rack up twenty takes of a single bar of music to get one line of vocal sounding perfect. They will shave milliseconds from parts to bring them right onto the beat, or build guitar solos up from numerous takes, just to find the best performance of a three-note phrase. It is the opposite to just getting a general vibe down on tape. Our band has quite a dense sound, with layers of vocal harmonies, so you can either blur this stuff or try and mix it with a lot of definition and clarity.
In terms of psychedelic music, there is scope to be both musical Jackson Pollock and musical Salvador Dali. You can capture the frenetic chaos of something happening in real time, and try and get a flavour of this on tape. Or you can build these totally lucid, slightly strange soundcapes delicately, capturing every detail.
As for McCartney, I never understood the fanaticism in trying to deduce whether it was his Hofner, Rick or Jazz Bass on each song. They all sounded the same in his hands. He took a Rickenbacker and turned it into the same dull thump as his Hofner. The brilliance is in the bass lines he composed not the gear; he was cooking with little more than flour and water when it comes to his tone.