> Rust, as an example, is a pretty difficult language to become productive in.

Perhaps it's experience with other languages, or the fact that I grew up when that sentence started with C++, but I honestly found rust pretty easy to get up to speed in.

Am I an expert? No, and until I get the chance to use it for a living that won't change. But getting from "I want to do X and Y with this language" to having done so was straightforward enough.