The PC hardware market is largely based around the needs of PC gamers. 20 years ago you could release a new CPU or GPU and there would immediately be new games pushing the limits and taking advantage of those new chips. But today the PC gaming market is largely subservient to the much larger console gaming market. Console hardware development moves much slower, the pace of graphical development has slowed, and thus the need for faster and faster chips has slowed as well.

I built my computer in 2020 and it still plays every new game at the highest settings. 20 years ago you could build a top of the line computer and then six months later Crysis comes out and makes it feel like a potato. That just doesn't happen anymore.