That is not entirely correct for Rust. I know because I helped a friend of mine debug the porting process. (Apple did not see fit to give me access to the hardware, alas.)

https://github.com/rust-lang/rust/issues/73908 has the full details.

(Also, not to be super pedantic, but this (among other things) is partially why I said "and is only going to get better in the future," that is, the support is generally good (I know, I am literally doing some of that in another tab right now) but not flawless.)