I learned GL in the 1990s on SGI systems. Shaders didn’t exist, poly counts were in the 100s, and textures were a massive processing burden. The rendering pipeline of course was quite different. And yet so much is the same! Code organization, data types, all is quite familiar, whether it’s OpenGL or DirectX or what not. The achievements of SGI engineers have literally benefited generations.
you are absolutely correct in that everything has moved on from "Fixed Function" of SGI, and how GPLGPU works (worked) - btw it's NOT GPL-licensed: Frank sadly made his own license, "GPL words but with non-commercial tacked onto the end" which ... er... isn't GPL... sigh - but everything commercially has now moved on to Shader Engines.
that basically means Vulkan.
however you may be fascinated to know, from Jeff's evaluation, that there are still startling similarities in basic functionality in not-GPL GPLGPU and in modern designs targetted at Shader Engines.
