it was revolutionary on a social level. I haven't met a single person who ever played a 4 player split screen game on a PS1.
while everyone and their mom played Mario Kart or Goldeneye in 4p split screen on N64.
if someone in your friend group owned an N64, that was the multiplayer machine everyone gathered to play.
the presence of 4 controller ports as the default instantly makes you see a console in a different light.
could we have played Crash Team Racing with 4 players? sure... technically... did anyone go out and buy a multitap and have that laying around? nope.
the same was true a generation later. I have never known anyone who owned a PS2 multitap. but we sure as hell played Halo, TimeSplitters 2, Nightfire, Mario Kart DD, and Cel Damage in 4p splitscreen on Xbox and/or GameCube... as well as 4p Smash Bros Melee of course, but that's not splitscreen related.