A lot of people have mentioned a lot of reasons, marketing, corporate support, etc...

I think a language technology needs at least one, but ideally a few, flag ship projects using it. It provides some examples for people to see, it shows the "why" and then it also connotes that it's living and good. I don't think it has to be big, just good. Ripgrep is a prime example, there are a few other smaller tools in Rust that are nice, well put together tools that do a nicer or better job than the old standards.

You can talk about why something is nice or better, but actually showing people that it is probably convinces more.