I have just released a prototype demo made with unity showing off PSX / PS1 style Vertex Warping.

I achieved this look through low poly models, baked textures and through using a shader graph and material to be putt onto the model to get this look.

The Vertex Warping Material has a property called "Cell Size" which can be adjusted to increase or reduce the vertex warping level

Vertex warping on the PS1 is the visible "wobbly" or "jittery" effect on 3D models, caused by the console's hardware limitations: its lack of floating-point precision for vertex positioning and its screen-space texture interpolation. Instead of smooth, continuous movement, vertices would "snap" to the nearest integer-based positions, and textures would distort as the console processed them incorrectly from a perspective viewpoint.