I used Copilot for a while (in a Rust codebase fwiw) and it was... both useful and not for me? Its best suggestions came with some of the short-but-tedious completions like path().unwrap().to_str().into() etc. Those in and of themselves could be hit-or-miss, but useful often enough that I might as well take the suggestion and then see if it compiles.

Anything longer than that was OK sometimes, but often it'd be suggesting code for an older version of a particular API, or just trying to write a little algorithm for something I didn't want to do in the first place. It was still correct often enough when filling out particular structures to be technically useful, but leaning on it more I noticed that my code was starting to bloat with things I really should have pulled off into another function instead of autocompleting a particular structure every time. And that's on me, but I stopped using copilot because it just got too easy for me to write repetitive code but with like a 25% chance of needing to correct something in the suggestion, which is an interrupt my ADHD ass doesn't need.

So whether it's helpful for you is probably down to how you work/think/write code. I'm interested to see how it improves, but right now it's too much of a nuisance for me to justify.