On the PS1 the lack of perspective correction when applying textures means that geometry will always retain its correct silhouette but the inner pixels may be displaced. Coupled to that, the most common texture format is paletted 16-colour.
That suggests one obvious way to minimise perceived texture warping: make sure your textures are low-contrast. Then it’s not going to be so obvious that you don’t have a large array of colours available per texture, or that some of the pixels are being painted out of place.
Two obvious art styles emerge: cartoon, ala Crash Bandicoot, where individual objects are so plainly textured that many of them aren’t textured at all; and brown/grey, which neatly avoids those reds and greens that your eye is most sensitive to. There are other options, of course, such as the variety of whites used by the briefly-faddish snowboarding genre, but those two are the more universal.
After that it’s just a question of the target audience. The PlayStation audience initially skewed towards older videogame players so the ‘realistic’ look is a better fit.
Low-contrast design also meshes well with low-resolution textures, especially when bilinearly fillered, so there’s also some technical advantage even elsewhere.
That said, never discount aesthetic choices. Why are movies from the ‘80s so much more likely to contain neon? Certainly not for technical reasons.