I don't think that's true. POSIX was written in the 90s, when many of these frameworks didn't exist. It's still nice that I can run GNU tools on basically any P

I don't think that's true. POSIX was written in the 90s, when many of these frameworks didn't exist. It's still nice that I can run GNU tools on basically any POSIX platform and I think many (developers) would notice its disappearance. User's probably won't notice, but they tend not to care about standards anyway.