I think it matters more for reading and collaborating than for writing. If you don't keep up to date with idioms, and your "fluent dialect" is three years out o

I think it matters more for reading and collaborating than for writing. If you don't keep up to date with idioms, and your "fluent dialect" is three years out of date, this won't impact your ability to write your own code. But it might pose a barrier if you try to read someone's blog post, or use APIs from recent libraries, or contribute to a newer project. Rust has the obvious seismic shifts like async, which are rare. But the community has a decent amount of "best practice churn" in some areas, like error handling, or async frameworks.