That's true only in comparison to languages with manual memory management. Higher level languages spare you the burden of being conscious about these things, which means Rust is naturally going to be more difficult to work with than, oh, I dunno, Ocaml.
From the other direction, coming from low-level languages: the other problem is that Rust's type system isn't powerful enough to express certain things that you, a competent C programmer, might be fully conscious of...and so you end up needing to fight the type system to get it understand something you're already aware of. To use a classic example, you can understand exactly how the lifetimes work in a doubly linked list but still find it more painful to write in Rust than in C.
From the other direction, coming from low-level languages: the other problem is that Rust's type system isn't powerful enough to express certain things that you, a competent C programmer, might be fully conscious of...and so you end up needing to fight the type system to get it understand something you're already aware of. To use a classic example, you can understand exactly how the lifetimes work in a doubly linked list but still find it more painful to write in Rust than in C.