To be fair, Rust is genuinely just as _hard_ in 10th language capacity.
I’ve spent most of my professional time in C, Ruby, and a decent amount of time dabbling around in functional languages. All of the core bits of Rust from this post more or less clicked immediately for me. The other features are there, but they’re typically not something you need to internalize to comprehend Rust as a whole.
The biggest hurdle—as for most people—was learning what the borrow checker is really trying to teach you about the structure of your programs and internalizing those lessons. But having some experience with RAII and good practices around manual pointer ownership in C helped pave a pathway toward understanding those concepts.