"Like unsafe Rust, but more convenient to use" is basically every imperative language around there, I still don't understand the specific niche that Zig intended to fill
Literally just D? I'm not really aware of other serious efforts to modernise C/C++. Other than Rust, the world became completely fixated on GC languages that were inherently meant for higher-level purposes. Full-fledged attempts at memory unsafe languages in this century have been few and far between.