Any C++ or C replacement will need to win the earths of mainstream OS and game console vendors, otherwise it will remain yet another wannabe candidate.
Those have already their own languages, alongside their own C and C++ compilers, and are only now starting to warm up to Rust.
Zig or any other candidate will have a very hard time being considered.
I disagree Zig is that great deal of a language, it would have been if we were talking about 1990's programming language ecosystem, not in 21st century.
Use-after-free problems should not be something we still need to worry about, when tooling like PurifyPlus trace back to 1992.
Use-after-free is a fact of life until something kills C, but the realities of language adoption are against that. Zig seems interesting and worthwhile in offering a different perspective on the problem and does it in a way more agreeable than Rust or the like for all those who love C and are adverse to large complex languages. The realities of language adoption are as much for as against Zig, large numbers of people are still getting drawn to C and Zig seems to do a better job addressing why so many are drawn to it than the alternatives.
Otherwise the only users are going to be the ones happy to do some yak shaving instead of the actual application code with the vendor tools.
It also ignores that C doesn't stand still, the competition is C2y, not C89.