“Leaning into functional” isn’t a hard thing to learn. However pure functional is when coming from an imperative language.

And that’s the point I was always making. Rust takes inspiration from different languages than Go. But there is a huge amount of borrowed experience you can lean on when switching between Go and Rust. You’re not starting from scratch.

Perhaps the real problem here is that developers stick to a subset of similar imperative languages and then moan that minor differences are hard to reason about?

I don't think the differences between go and rust are minor.

You aren't starting from scratch in the same way that if you have written javascript you aren't starting from scratch writing c++.