Sqlite is 6 MB and can compile in 2 seconds on msvc.
It's 25 years later, if you are waiting for an hour to compile a single normal C program, there is a lot of room for optimization. Saying C doesn't compile fast because 25 years ago your own company made a program that compiled slow is pretty silly.
Single file C libraries are fantastic because they can easily all be put into more monolithic compilation units which makes compilation very fast and they probably won't need to be changed.
Have you actually tried what I'm talking about? What are you trying to say here, that you think single file libraries would have made your 1 hours pure C program compile slower?
