I don't think it is unusually difficult to find Rust programmers. The challenge is finding Rust programmers who also have expertise in systems software development. Rust was designed to be a systems language but ironically it primarily seems to attract developers that do not have expertise in systems software.
This isn't necessarily a problem. C++ and Rust can coexist pretty well in practice, and Rust is a good entry point for learning how to write systems software.
Sadly I have found the flip side, too: as someone with a systems software interest/background (I wouldn't say expert), the # of jobs in the Rust ecosystem that are not glorified webdev/microservicing (or worse, crypto) is actually quite small.
So I guess I wouldn't be surprised that the applications are trending that way, too, as that is where growth is happening right now it seems.
That's the flip side of the same coin as your parent comment, I guess - because Rust is more accessible than C or C++, a lot of people have started using it for stuff that's not hardcore systems software, and as a result it's not as good a filter for that stuff as C and C++ are.
On the other hand, we use Rust on the backend of our web based saas product, and it serves as a great filter for quality developers for us.
This isn't necessarily a problem. C++ and Rust can coexist pretty well in practice, and Rust is a good entry point for learning how to write systems software.