I can't speak for the original GLQuake on 3dfx hardware, but on OpenGL-compatible Quake engines (which include modern Quake source ports such as Quakespasm, Iro

I can't speak for the original GLQuake on 3dfx hardware, but on OpenGL-compatible Quake engines (which include modern Quake source ports such as Quakespasm, Ironwail, and vkQuake), bilinear texture filtering is an option that can be turned off. I play on vkQuake with nearest-neighbor texture filtering, square particles, and the "classic" water warping effect and lighting effects, alongside 8x MSAA, 16x anisotropic filtering, high-resolution widescreen, etc. This keeps the art style consistent with the look of the original Quake, while still allowing for the benefits of hardware 3D acceleration.