Man of us are already competent in C and/or C++, so to make a move there has to be a big value prop if it's a large investment. I'm not saying there's not, but most of us aren't deciding to pick up C, C++ or Rust from scratch.
On a personal note, learning Rust has made me a much better C++ developer. I'm more conscious of various degrees of aliasing and multiple ownership, to the point where much of the C++ I've written of late is inspired by the borrow checker's conventions. And since what I do is usually executed concurrently, I've seen a concrete decrease in bug count and severity without cost in performance. Which means the time investment in learning Rust has paid off, in my opinion.
Just to give a possible example, given everything that Microsoft has been doing about Rust.
On what concerns Windows systems programming, Rust must be able to integrate with .NET, allow mixed mode debugging, authoring of COM/UWP, use of the GUI frameworks, just as easy as VC++ allows us to.
So I am eager to get to know about whatever Microsoft might announce in this regard.
w.r.t debugging, I haven't had much trouble mixing with C++ but I haven't tried to do anything through C#.
That is the difference between using C++/CX, C++/WinRT or the existing Rust libraries.
So how do you integrate Rust with VS debugging tools?
I'd love to see that trick.
But that being said, when you see that the majority of vulnerabilities are essentially memory lifetime issues (https://msrc-blog.microsoft.com/2019/07/22/why-rust-for-safe...), you realize that we are all human. So something like Rust could help--especially new developers.