This is what I have struggled to understand about Zig. It seems pretty much like C in a mental model aspect - you are responsible for everything. It's slightly better than C, but C already runs on everything on the planet and can be made secure even if painfully so. So what niche is Zig aiming to fill?

no, null pointers are enforced safe at the type level in zig, as are array bounds, this eliminates huge classes of errors, so you are not "responsible for everything". unlike c, you often (unless highly tuned performance is needed) do not have to resort to opaque void pointers, and the compiler gives you typesafety on that, another major footgun in c.

also operators and integer types are unambiguous, and there is no UB in safe compilation modes.

It's arguably much better than C, not "slightly better than C"

Zig detects memory leaks pretty well when you build it using -Doptimize=Debug.