The benefits of advanced static and dynamic analysis tools for C shine through on questions of semantic correctness (look at Coverity, Frama-C and PVS Studio), not memory safety (though they do reason about memory safety). You can achieve perfect memory safety (no false negatives and arbitrarily few false positives if you write appropriate abstractions around unsafe) with comparatively simple static analysis built into your compiler... but only if your language is designed to permit it.

In C, perfect static analysis for memory safety is impractical, and dynamic analysis is time-consuming and cannot preclude false negatives. We should work on porting tools which heuristically warn about semantic correctness concerns from operating on C to checking Rust programs, and this is probably necessary in order for some C or C++ programmers/projects to switch, but it doesn't pertain to the question of how much mental overhead there is to writing memory-safe code in either language.

Because ultimatelty they're imperfect.

Sure, C+static analysis is good enough for many situations. But it can't compare with the guaranteed safety offered by Rust.