Rust is extremely interesting, but here's the thing: at this point it's going to be hard to dethrone a language like C++. Far too many excellent libraries exist for C++ and even recent but slightly more mature languages like Go will need at least a decade to catch up. Sure, you could write bindings but it's never going to be quite the same.

This is probably true. It also applies to Java, C#, PHP, COBOL, x86, and ARM. Although, it might be noted that various things on that list dethroned others in certain segments. Still doesn't matter. You don't have to dethrone anything.

Just build an advantageous ecosystem with a good chance of short-term and long-term commercial support. Do that right, there will be uptake that can slowly build into something competitive. We've seen it happen numerous times with Mathworks (MATLAB), Borland (Delphi/Pascal), Eiffel (Eiffel), Microsoft (C#), Sun (Java), Google (Go), Mozilla (Rust), and Apple (Swift). Really useful and superior tech can also attract people into closer-knit, small, and high-quality communities as we see with Haskell. So, I tell people not to worry if vast majority will use your stuff. Just worry if a good chunk of them will find it useful enough to pick up and extend. Then you might make it.

Note: A cheat I've already mentioned is making your language or whatever integrate with a popular one and its libraries. Clojure, in an anti-LISP world, is proof of how unusually effective that can be. The typical example is how most C alternatives can compile to C or use its libraries.

If you look at big C++ apps like Firefox or AAA games, most of the third party libraries are used through C apis. Even commercial libraries written in C++ often have C based APIs because of historical binary compatibility problems in C++ linking. Is safely wrapping a C api in C++ significantly easier than wrapping it in Rust?

I'm curious about Rust but haven't tried it enough yet to form an opinion.

Intend to spend this years Christmas holidays catching up on Rust.