When the PS1 hit its stride in 1998/1999, many of the PC games were already of PS2 quality to a degree that the PS1 could never have achieved: Unreal, Colin McRae Rally, Quake 2.
1998 onward was already past the mid-point of the PS1 mainstream shelf life. The Dreamcast was coming out, the PS2 was going to be launched at the end of 2000. At that point it was already coming up to four years old, the fair comparison is PS1 games against PC games from 94 and 95.
Please take an honest look at PC games from the late 90s. How many graphically match Silent Hill 2 or Metal Gear Solid 2? Half Life as it was already looked like warmed over garbage in 2001.