If you are willing to hand code intrinsics it doesn't really matter what language you pick from a performance perspective. Rust consistently shows it has better performance than c++ in code that does not hand code intrinsics. If cpu(not gpu) based performance is all you care about there is no reason to pick anything but rust. Modern c++ devs have no trouble with the borrow checker either they are already doing all the things that keep it from complaining. The reasons someone might not pick rust involve integration with existing code, the complexity of the language, and the depth of it's dependency trees. The complexity argument certainly doesn't lean you towards c++ or probably anything with an llvm back end. The openbsd approach to c is probably as simple as you can get these days short of forth or something equally obscure. Dependency trees are deceptive. We all have deeper trees than we think we do, but the rust front end itself has well over 100 crates in its tree...

All that said, I use rust for everything.