Situation is everything.

speed matters when it comes to systems-level logic/code. Zig strikes that balance very nicely.

Industry cares at the systems level. If a "safe" kernel is 4x slower (compilation, run-time) and there is an "unsafe" option that is just as secure, outside of a cadre of philosopher kings/queens (more power to 'em), practical teams will hit that unsafe performance boosting switch every time.

C is as safe as the situation & the code dictates. Zig makes it easier to be safe in most situations and excels at promoting systems-level safety.

App level, or app API? Where there is more of an x-factor? rust has a great use case. In "user-land", availability matters almost as much as performance.. An app that always crashes is not as valuable as a slower app that never crashes...