I’ve not worked on console games but in terms of texturing I suspect the ” these are way more than just pixel art…” comes from having a high res image/painting and applying an 8 bit dithered palette. I spent about a year of my working life creating 8 bit palettes for CD-Rom assets / movies where you needed to optimise a single 8 bit palette such that it could work across a range of assets. The aesthetic of the first image you posted to me looks like it comes from using a custom 8bit palette. I can’t see obvious dithering – it’s more like it’s been posterised.
I might be wrong but isn’t the look of PS1 basically driven not by the models/textures but by the capabilities of the hardware… the models/textures started out higher res but got crushed down by what the hardware could render.
