I take your word for it.

It's just that my Win3.1 computer was too slow for me to remember the acceleration.

Even DirectX had predecessor, back in Windows 3.1 with the Win32s extensions, it was called WinG and offered hardware accelerated blitting.

https://en.wikipedia.org/wiki/WinG

I remember playing something that ran with the Win32s extensions and was similar to Wolfenstein 3D, but it was 3D, and I don't think it had anything to do with 2D acceleration.

Also remember the glorious Fury3 game.

https://www.youtube.com/watch?v=6_8tSpXLuK8