Ah, but then you have potential interop and portability issues. C11 isn't yet universally adopted, and there are some dark corners out there where even ANSI (C89/C90) is not quite embraced and original K&R is holding out.

I think the jury is out on Zig and Odin (but I like Zig a lot, in particular), but I feel Rust has hit a tipping point - like Go, Python and Java - where there's too much production code out there for it to disappear in the next ten years.

If you were to ask me about languages where that might not be the case in ten years, I'd point to where usage is not very production oriented (R, Julia), or where people have had a good try and decided they want to pull back investment (anecdotally, Ruby and Scala seem to be on that curve right now).