I think it depends on the games. Some art designs hold up better, some games were hindered by excessive fog or bad performance, etc.
Let me put it this way. N64 games like Mario Kart 64, AKI wrestling games, Smash Bros, Mario 64 and Goldeneye look amazing compared to most PS1 games. They look clean, run well, good draw distance, etc. Games with very blurry textures and fog really annoyed me. Its often gave a muddy picture that could leave people prefering the most crisp visuals of PS1.
Meanwhile games like MGS, Tekken, GT and other 3D games looked solid on PS1. They were crisp, ran well, that was good use of the hardware.
Hence, you gotta at games individually. But in many cases I may have prefered PS1 ports because less muddy textures, better sound (more music in some games), FMVs, etc.
Lastly, that was a very experimental era in 3D gaming much of which I didnt enjoy. Its worth noting there were many notable games relying heavily or entirely on 2D assets which were great on Saturn and PS1. N64 made a bigger push on 3D games to its detriment.