Only if "defect count" is what you care for.
What if you don't give a fuck about defect count, but prefer simplicity to explore/experiment quickly, ease of use, time to market, and so on?
I might still want Zig just fine. E.g. because I know C well, and it's a better C. Or because of the ease of interfacing with C/native libs. And several other reasons.
Zig allows custom allocators pretty much everywhere, right? Would it be impossible to provide it with a GC-based allocator for increased convenience at the cost of a little performance for programs (or parts of programs) where convenience is preferred? Perhaps libgc could be an inspiration here.
I probably can "beat that", because e.g. breaking things into functions increases simplicity and being able to explore/experiment quickly.
Whereas eliminating defects with a type/lifetime checker you need to hand-wrestle, not so much.