I get what you're saying, but it's worth also mentioning that your full 3d SNES game example is pretty much exactly what games like Star Fox[0] did, back in the early 90's. The Super FX chip is inside the SNES cartridge. From the wikipedia page:

> The Super FX was so much more powerful than the SNES's standard processor that the development team joked that the SNES was just a box to hold the chip.

Really interesting to read about, but there was a whole selection of other chips that various SNES games took advantage of: [1]

[0] https://en.wikipedia.org/wiki/Star_Fox_(1993_video_game)

[1] https://en.wikipedia.org/wiki/List_of_Super_NES_enhancement_...