The distorted textures and weird triangle clipping issues are exactly what you'd expect from an unoptimized port to a platform that doesn't support perspective correct texturing or depth testing.
I had the opposite reaction. As someone who was on team PSX, the wobbly jank is pleasingly nostalgic. Didn't someone say that the limitations and artifacts of the obsolete media of the past become the sought-after aesthetics of the future?
As someone who was team N64 I do agree PSX has more of a "trademark look" compared to the N64 which is pretty much just a very limited version of a modern graphics rasterizer.