Google and most other software kings chooses C++ for backend. If you think you know better than them feel free to use the hype lang of the day. Rust will be gone in a few years.
I don't think that conflicts with my comment. Just because Rust is ready for production doesn't mean that C++ isn't also ready for production. For what it's worth, Google are increasingly choosing Rust for new projects. As are Microsoft, AWS and several other large software companies. Obviously it doesn't usually make sense to rewrite old projects that are already in C++.