People who use Rust aren't using it to solve real world problems, they're using it to scratch a novelty itch.
D is a tragedy in my opinion. It's an excellent language that just doesn't fit the political needs of any of the big players.
We have Swift which is a worse version of C#, we have Go, we have Java. Why don't we have a single language so that we can do cross platform development and abandon web browsers and javascript? Because politics. Every company needs to toot its own horn and suck up smart intelligent people so that they don't create a real competitor, and so we have a dozen languages that share 95% of the features and are all incompatible with one another and no one sane enough to say this is crazy, I'm going to take my FAANG money, move to a place with cheap rent and put an end to this madness.
It's only a game developer of all people, Jonathan Blow, that's doing it and his creation is a C++ replacement for games, not general purpose software. Sigh.