Aren't almost all new projects that otherwise would have been written in C or C++ good fits for Rust?
The C++ ecosystem is too strong.
There are many industries like game dev and audio dev where C++ is not going to be replaced any time soon, even for new projects.
Also plenty of apps that need high performance crossplatform GUI will probably keep relying on QT. Apps like Da Vinci Resolve or Autodesk Maya.
Certainly a lot, and most new C/C++ (and even Go) projects will mention that they considered Rust before choosing a different language.
Aren't almost all new projects that otherwise would have been written in C or C++ good fits for Rust?