I use Copilot mostly with C++, and found that frequently it has problems with simple codebases also. Beside that it rarely suggests anything newer than cpp17, and very frequently it suggests C snippets...
I don’t know how this is in more established languages, but in my experience there is a big problem in conflating versions.
In Elixir, I constantly get code with API calls that conflate different versions. As amazed as I can be in some contexts, with fast moving libraries I get nowhere fast.
I’ve been wanting to try vibes based coding, but can hardly get off the ground.