IMO the STL is a lot easier to get a grasp on as a newer developer than Rust’s borrow checker or lifetime system.
I actually feel like Rust’s borrow checker is more difficult to learn for experienced devs. We’ve got a trainee in Rust and for her, it’s just a normal thing that variable slots hold ownership and can lend it and get it back. She does sometimes still struggle with when to clone and when to borrow, but she’s getting there.
As for the lifetime system, no one on our team really gets that one. 🙃
But (that’s because) you rarely need it.