No, at the very least I would add a (reserved) stdc_ prefix to all stdlib functions (and defines, and header filenames...), and keep options open for API versioning (e.g. stdc2_...).

That way we could also get rid of all the random reserved identifiers we need to (theoretically) adhere to now.

That's a good start, at least for function names, not sure if I would use the same logic for everything.

In practice I find the prefix style better than namespaces, as a way to avoid information scattering.

Snake case would probably win the race, but I am not sure that many old-timers would be ready to let go the old habit of abbreviated function names.

After a while we don't see it for what it is, but I think that most of the naming is ugly, especially the string functions...