[tialaramex]

Actually Unsafe Rust is arguably more fraught than C because the rules in Unsafe Rust are just as tough as they are in Safe Rust - much tougher than C - but in Safe Rust the language and libraries promise to take care of that, whereas in Unsafe that's on you. So choices which are in fact harmless in C will result in UB in Unsafe Rust.

The benefit is that unsafe passages of Rust are rarer and should be safely abstracted from APIs for use by Safe Rust. Mellisearch seems to often (but not always) provide safety rationales for unsafe code, explaining why whatever is done is OK. I don't understand this domain in enough detail to comment on the quality of the rationales.

[pdimitar]

Yes and no, unsafe Rust still holds a number of invariants, wherever if you just go on your own writing C you have zero.

I prefer the number of guarantees / invariants that's above zero.