You are right there is no reason mobiles can't run Rust/Go/Python. But actually they don't, because there is no infrastructure and no tooling to build mobile apps using these languages. And this is the big oversight of the creators of these languages. All these languages we love so much as developers will die. Not because they are missing generics or error handling or coroutines or a static type system or other nifty language features. They are simply missing tools to create mobile apps.

I think you're vastly overstating the case saying these languages will die..

The majority of code we write runs on servers, even if its ultimately in service of a mobile/web client. Even if mobiles didn't support them, that doesn't mean these languages will die. The servers still have to run.

Creating the tools to run them on mobile is a solvable problem. Rust is already supported in the Android platform [1]. It takes more work to write an application in a non-standard language but its doable. Just saying don't worry about every other language dying out because of mobile, that won't happen :P

[1] https://source.android.com/docs/setup/build/rust/building-ru...