The main point of Rust is correctness, not performance. Performant code is a nice to have - but when the two are in conflict, correct code wins every time. How can one ever be confident that your Senior C++ devs are writing code that is free of subtle bugs? Are you going to look for professional Haskell or Ocaml devs too, for a proper comparison? Those folks ain't cheap, either.
I maintain large scale C++ code that hasn’t had a bug in production for 5+ years. I do it using lots of system level tests. So it is very much doable. It has nothing to do with the programming language. Yes some languages (Haskell for example) completely eliminate a large class of bugs, and I would prefer to use languages like that, however the world runs on C/C++. So having solid C++ skills is great for your career.
