Since we're 10 years on at this point, I feel pretty confident saying the plateau to my eyes landed somewhere between the PS4 in 2013 and Pascal (GeForce 10-series) in 2016.

I've kept playing games and upgrading my GPU every other generation, and they're still fully utilized, but I can't really see where the additional compute and money is going. My biggest visual upgrade during that time was actually going from LED to HDR OLED which is something that requires virtually no additional processing power.

I still think it pretty much was the last major generational upgrade in graphics. An early PS3 game looked night and day better than a late PS2 game. Meanwhile, an early PS4 game looked only marginally better than a late PS3 game, and most PS5 games don't look noticeably better than a PS4 game.

I don't mind that graphics have plateaued, because they aren't the important bit. If anything, I would rather that devs stop trying to chase graphics and make more games with shorter dev cycles.