Scala (the v2 series, I haven't used v3 at all) was, to a first approximation, a language of, by, and for graduate students in language research that accidentally escaped the lab and briefly took over the data engineering space. Multiple competing category theory libraries, vicious fights about which was more pure, continued debates about the beauty and confusion of implicits resolution, the list goes on.
Rust seems downright blue collar in comparison. So much of the Rust I've written and the teams I've been on, and the open source we've used has been exactly the kind of stuff we would have used Java for 15 years ago. Boring practical stuff. Same goes for the community interactions. "Here's how to get this thing working", "here's a better way to do this", "maybe you didn't know but here's a cool way to speed up that section", etc.
Sure, if you go into the development process of The Rust Language Itself, people are talking about compiler minutiae and using datalog to do type resolution, but that _really_ has not been my experience as a user. Me and everyone I know use Rust like the Golang people say they use Golang.
In fact the crux of the difference between the Rust community and the Scala community has been Rust's continued obsession with developer experience/user experience (whatever you want to call it). The error messages, the tooling, etc. Scala had none of this. A disproportionately significant section of the Scala people were obsessed with type theory, quite often to the detriment of usability/programming experience.
I respect your experience with the Rust community but I haven't had this experience at all. Totally unrecognizable to me.