Again, you misunderstand. Both Zig and Rust have much less UB than C. The delta between Rust and Zig comes at a cost to language simplicity and to more testing. You're guessing that that cost's negative impact on correctness is smaller than that positive delta. It's a reasonable guess, but so is the opposite one, and neither is more proven than the other, which would be my guess (while I don't write safety-critical code these days, I worked on safety-critical realtime software where a bug or even a later response could cost the lives of many people; in such correctness-critical domains C is preferred over C++ despite being less safe), although I would even more confidently bet that the real difference, whichever way, is small.