The type system is great and gives extremely fast feedback. The performance wins are also incredible, it just feels like you're throwing 100s of megabytes of RAM away and 10x latency when you don't choose rust now, and for little reason. The testing tooling is really solid - property testing, fuzzing, mutation testing, etc, is all easy to use. Code structure with nice abstractions that don't become spaghetti is nice (traits, enums, etc). Static binaries as a production artifact is really nice. Supply chain story is pretty solid with cargo-vet.

It's hard to come up with anything where I think Rust isn't "best in class" other than compile times.