i'd argue that 3d-accelerated graphics from that era is still true 3d acceleration. of course, back then the pipelines were mostly fixed - nothing like programable shaders - but you're passing in 3d-coordinates, generating some matrices to determine the MVP, passing in some textures, and getting most of that "heavy lifting" of getting the pixels on the screen from the API & card.

> they were basically very fast (for the time) 2D triangle renderers.

that's still true of GPUs today :) in fact, with the exception of h264/265 encode/decode, and "AI" - that's all that graphics cards have ever done!