Within the tiny set of scenarios where Rust is applicable as of now, isn't it completely dominating?
It's dominating in hype and excitement for toy and pet projects. This is just the first few steps. Too few people have dabbled enough yet.
The next step is enough stability/maturity that more open source and maybe fang infrastructure can use it. And when the reasoning behind this becomes widely digested, most "green field" projects will choose Rust.
But that may be ten years away?
But that's not the right comparison. The use of the C language itself is a rounding error compared to all the languages that replaced it. Java, C#, C++, Python, Javascript, Go, they all replaced most use cases of C in modern programming. Rust is just attacking the last vestiges of C's usefulness.
Illustrates why projects don't do this:
> If you're breaking backwards compatibility anyway, why not go all the way?
Rust usage, even with millions of dollars of marketing and eleven years of hype, is still almost a rounding error in terms of usage.