Don't get me wrong: C++ sucks. But as far as Rust goes you are way too optimistic. In the context of game development, Rust suffers from a lot of the same problems as C++. Features like fast build times and debuggability actually matter there. It's not memory safety why game dev people are starting to get fed up with C++, it's the slow build times and feature creep of modern C++. In those areas, Rust looks even worse than C++.