> Ignores that there is already a well established C alternative: C++.
I don't consider C++ an alternative to C.
I see it as "a more modern language", but there are "even more modern" languages nowadays. The only reason I see to pick C++ instead of something like Rust would be if there are very mature C++ libraries and it is not practical to call them from the newer language. Typically for computer vision (or maybe just linear algebra?), I would still go with C++, probably? But in terms of language, I would pick any modern language over C++ if they do the job.
What about C, then? I use C when I want interoperability. Nothing currently beats C in that domain, as far as I know. I often wrap whatever I have into a C interface just for that.
IMHO, the interesting question about "replacing C" is really this: if you had to design a modern language meant to compete with C's interop story, how would it look like? Not sure if such a language could have memory-safety, for instance? Could such a language be meaningfully nicer than C?
Disclaimer: I don't know Zig.