Go is a garbage language which tries to incrementally improve upon C but is afraid to do any real innovation. It's awful.

PHP is not at all more productive than Rust. You might write code a little faster, but PHP is the worst programming language in modern widespread use, so the gains from typing are all lost by PHP code being more prone to bugs and less easy to reason about. Worst type system known to man.

You could replace any of the other languages you mentioned with Rust as well, while maintaining positive net productivity (contingent on availability of libraries, but let's assume we're talking about the language itself).

Nobody says it was the answer to everything anyway, the claim is that it is the future of programming that would otherwise be done in C and C++.