“One”? Wired up how? There is a huge difference between the best and worst. They aren’t fungible. Which one? How long ago? Did it even support FIM (fill in middle), or was it blindly guessing from the left side? Did the plugin even gather appropriate context from related files, or was it only looking at the current file?
If you try Copilot or Cursor today, you can experience what “the best” looks like, which gives you a benchmark to measure smaller, dumber models and plugins against. No, Copilot and Cursor are not available for emacs, as far as I know… but if you want to understand if a technology is useful, you don’t start with the worst version and judge from that. (Not saying emacs itself is the worst… just that without more context, my assumption is that whatever plugin you probably encountered was probably using a bottom tier model, and I doubt the plugin itself was helping that model do its best.)
There are some local code completion models that I think are perfectly fine, but I don’t know where you will draw the line on how good is good enough. If you can prove to yourself that the best models are good enough, then you can try out different local models and see if one of those works for you.