I used to use Github Copilot, then switched to Codeium based on an independent comparison (video). I might switch back or pick up yet another tool based on updated benchmarks. I also briefly tested out IntelliJ’s built-in solution. In all cases, I use it like you — as a fancy autocomplete.
The one thing I learned to do that makes me more productive is having a keyboard shortcut set up to quickly enable / disable the autocompletion. (For Copilot, it’s Ctrl-Shift-O. I bound the same keystroke for Codium.) This lets me focus on my flow when coding most of the time, without the distraction of wrong auto-suggestions, and then use the AI only when I know it’s going to be useful. Before learning this “trick”, I often spent more time reading and rejecting garbage suggestions than doing actual coding, and losing concentration. As you note above, the AI is best at sequences of repetitive or obvious stuff.
In the past, I periodically tried the other things that LLM coding tools provide, and so far I have always been disappointed. I’m talking about things like the chat interface inside the IDE that lets you ask the LLM to rewrite code for you. I tried that with Codium, Copilot and the IntelliJ AI solution. In all cases, the results were dismal. I might try it again.