> GPU hardware started to shift towards a generic SIMD design. SIMD units were now executing all the different shader types: vertex, pixel, geometry, hull, domain and compute. Today the framework has 16 different shader entry points. This adds a lot of API surface and makes composition difficult. As a result GLSL and HLSL still don’t have a flourishing library ecosystem ... despite 20 years of existence

A lot of this post went over my head, but I've struggled enough with GLSL for this to be triggering. Learning gets brutal for the lack of middle ground between reinventing every shader every time and using an engine that abstracts shaders from the render pipeline. A lot of open-source projects that use shaders are either allergic to documenting them or are proud of how obtuse the code is. Shadertoy is about as good as it gets, and that's not a compliment.

The only way I learned anything about shaders was from someone who already knew them well. They learned what they knew by spending a solid 7-8 years of their teenage/young adult years doing nearly nothing but GPU programming. There's probably something in between that doesn't involve giving up and using node-based tools, but in a couple decades of trying and failing to grasp it I've never found it.