Its not the same rock textues tho.

its the same style. Because its the same studio.
If Larian makes BG3 it looks like a Larian game, its gonna feature some very catholic architecture and renaissance statues and tiled floors, Larian likes that shit.
Meanwhile if Obsidian were to make BG3 then it would look an Obsidian game, by which iw ant to say like absolute dogshit featuring ugly character that creep onto your PC