Technology was advancing at breakneck speed back then. From 1994 to 2004, we went from 2D platformers on the SNES to Far Cry and Half Life 2 (realistiс 3d games with physics). And in between (still during these 10 years) there was the PS1 era with 3D, but ultra pixel graphics, so the transition from PS1 to PS2 seemed like a miracle. Characters in video games (going from PS1 to PS2) started to look like people, not like cubes with pixelated face texture. And all of this happend in 10 years. Just in 10 years games switched from looking like interactive 2d cartoons (where you walk from left to right) to realistics games with real stories.
The youth in the 2000s (who started playing games on PS2, XBOX and Gamecube) really considered PS1, N64 games as outdated retro games. They really looked like that compared to PS2 games. And NES and SNES games even more.
And also whole genres just started to beign invented during this period. We first saw Diablo, Warcraft, Resident Evil, GTA started as small 2d game and went to phenomena on PS2 and all of this still in those 10 years.
And the thing is (why the 1990s games feel dated) - the early games in these new genres were really clunky, and people who were used to playing new games just couldn't play the yearly games.
-People who grew up playing Warcraft 3 just couldn't go back to Warcraft 1, that game seemed clunky.
-People who grew up playing GTA3 VC and SA just couldn't go back to GTA1 and 2.
-People who grew up playing Half Life 2 just couldn't go back to DOOM2
And there was only 4 years between GTA1 (1997) and GTA3 (2001). It's crazy how we went from GTA1 to GTA3 in just 4 years. From GTA1 to San Andread in 7 years. Now it took almost twice as much time from GTA5 to GTA6 (12 years)
And over the last decade (and even a little more), gaming technologies (graphics, physics, details, aliveness of the worlds etc) seems to be only degrading from Batman Arkham Knight 2015 to Suicide Squad 2024 from GTAV 2013 to Saints Row 2022 from Skyrim 2011 to Avowed 2025 from Uncharted 4 2015 to Forspoken 2023. Thats why this 1990-2000 era seems like something else.