I'm a fan of Rust for things like a missile control system or a stock exchange, but not, say, writing a CRM. I'd gladly write a CRM in Zig however, given the proper library support and tooling. Why? productivity. In my experience it just takes 2-3x longer to get the same thing done in Rust vs. something like Zig/Crystal/Go and certainly vs. Ruby/Python/etc. For extremely mission critical code, this is fine, but for most startups I would argue it probably isn't appropriate.
Definitely staying tuned as Zig develops.