The graphical quality between a 4090 and a Series X in most cases is miniscule, you can notice it but if you're playing the game you probably won't notice anything different.
The PC experience goes far beyond that though, it's not just about the GPU (even though it plays a big part in that visual fidelity is +++ on PC with titles like Alan Wake 2's PTGI with ray reconstruction etc.
The other benefits being consoles don't have ultrawide support so you lose some immersion there depending on the game. I've been ultrawide gaming since they first came out and can never game on 16:9 any more because it just doesn't feel right, like portions of my left and right peripheral vision are missing
On top of that FPS games with mouse and keyboard are superior vs a controller. Granted this is preference but twitch movements and quick reactions are simply not possible on a controller.
Plus it's quite hard to drop to a locked 30fps on consoles if you want visual fidelity or 60fps if you can sacrifice some visual quality for a 60fps output. PC is just higher quality textures, shadows, GI, AO, everything. For many the extra cost of a GPU alone covers those benefits as depending on the game, these are things you do notice. This is why I've not bothered with buying a console since the Wii and only caved with a PS3 when GTA5 came out and then The Last of Us as they had no PC release set in sight, and a PS3 back then was no more than £150 anyway so it was an easy decision.