Anyone who has managed to become proficient in C++ is smart enough to be proficient in Rust. The only too difficult part is adapting to the rust way of doing things and some refuse to.
I'm not sure you're paying attention. The people who are saying Rust is too hard are the Rust community itself. They said so in Rusty's annual survey. The ones who participate in it are Rust users who feel strongly about the topic to participate in their governance.
It's Rust users who say Rust is too hard. There is no way around this fact.
I agree completely. But I'd reword your statement slightly as "Anyone who has managed to become proficient in the language that is notorious for being one of the most complicated and convoluted languages in existence, with the most footguns per line of code and a CVE record that proves its difficulty, ..."
It changes the conclusion just a tad.
So building libraries must be easy, that's totally why you can become an architect over night ... What a stupid argument you delivered