Just learn whatever you currently need. If you know a few paradigms, learning a new language of the same paradigm is easy-peasy and can be done rather quickly (well at least being be productive with it, doing stuff idiomatically often takes a little bit longer).
That said, Rust IMO is a language that makes sense to learn anyway, since it also teaches you to program in a nicer way (not just true for Rust, there are other languages that have this effect as well, such as Haskell etc. generally languages that introduce something really new (i.e. a new paradigm)). Generally it makes sense to learn multiple languages, as each brings you new ideas. But on the other hand it makes sense to learn one language really well (I'd recommend that being Rust, as it can cover so many use-cases and is generally designed nicely (it fills a sweet spot between mutability and functional programming IMHO).
I'm mostly using ChatGPT4, because I don't use vscode (helix), and as far as I could see it from colleagues, the current Copilot(X) is not helpful at all...
I'm describing the problem (context etc.), maybe paste some code there, and hope that it gets what I mean, when it doesn't (which seems to be rather often), I'll try to help it with the context it hasn't gotten, but it very often fails, unless the code stuff is rather simple (i.e. boilerplaty). But even if I want the GPT4 to generate a bunch of boilerplate, it introduces something like
// repeat this 20 times
in between the code that it should actually generate, and even if I tell it multiple times that it should generate the exact code, it fails pretty much all the time, also with increased context size via the API, so that it should actually be able to do it in one go, thegpt4-0314
model (via the API) seems to be a bit better here.I'm absolutely interested where this leads, and I'm the first that monitors all the changes, but right now it slows me down, rather than really helping me. Copilot may be interesting in the future, but right now it's dumb as fu... I'm not writing boilerplaty code, it's rather complex stuff, and it fails catastrophically there, I don't see that this will change in the near future. GPT4 got dumber over the course of the last half year, it was certainly better at the beginning. I can remember being rather impressed by it, but now meh...
It's good for natural language stuff though, but not really for novel creative stuff in code (I'm doing most stuff in Rust btw.).
But GPT5 will be interesting. I doubt, that I'll really profit from it for code related stuff (maybe GPT6 then or so), but we'll see... All the other developments in that space are also quite interesting. So when it's actually viable to train or constrain your own LLM on your own bigger codebase, such that it really gets the details, and gives actual helpful suggestions, (e.g. something like the recent CodeLlama release) this stuff may be more interesting for actual coding.
I'm not even letting it generate comments (e.g. above functions) because it's kinda like this currently (figurative, more fancy but wordy, and not really helpful)