The hardware graphics acceleration stack is heavily shader-based now, so there's less and less graphics code being written in systems languages like C. In a way, people are still writing their own graphics engines, it's just for such a different platform from the unusual Turing-computer CPUs that all the old techniques go out of the window.

Nothing stopping you from writing it the old fashioned way though - you can just keep generating a single screen texture in the CPU and let the GPU idle!