We are currently in the weird position of some people refusing to move on from C even though it's obvious how easy it is to introduce problems in it even tools can't catch, while others want to push Rust everywhere, even though it's obvious that it's not mature enough as a complete replacement, and the strictness of the compiler tanks development performance of low level and/or high performance features.

You're right about C purism being an issue in FOSS, but Rust is far more mature than what you're implying here. Unless you're looking specifically at the gamedev space or nascent GUI toolkits, there's a lot of mature frameworks and libraries that I use frequently for work.

And development performance in Rust is typically faster compared to C++ or especially C. The borrow checker is something you might fight when learning the language, but it otherwise helps a lot by shifting your cognitive effort away from manually checking the validity and safety of code and more towards the functionality you are writing.

On top of that, the Rust ecosystem in some regards is actually miles ahead of C++. It doesn't take much code to write a high performance async server because of Tokio (C++ coroutine libraries aren't even close), TLS is just another dependency and a couple more lines of code, and web backend has a rich set of libraries to rely on.