I’m not quite sure what your point is here? N64 (and wii) was fixed function, no shaders at all … unless you count rsp programming for vertex ‘shaders’ but that was relatively uncommon and certainly wasn’t done in earlier n64 titles.

The api borrowed a lot from opengl and the opengl red book was required reading! I dont understand your C++ comment; only directX is C++. Vulkan and the playstation sdks are all C, and the programming language used to call into the graphics api has nothing to do with the look of a game.