> Rust is actually that hard that only a small share of developers will ever master it

Kind of disagree here. Don't really think it's that much harder than C++, just hard in a very "annoying" way. Which, given its purpose, is a good thing. Making the borrow checker happy is mostly an exercise of going up and down method call chains to see where you screwed up. Or verbosely wrapping stuff in Arc<Mutex<T>> to make it a shareable resource.