I'm an artist and haven't used a mouse since somewhere in the 00's when I developed some RSI in my index finger while working in the Flash animation mines.

Annoyances: games that require you to push the cursor against the edge of the screen to move the view, app/website developers who force tiny scrollbars that constantly hide themselves despite me setting the OS to never hide scrollbars, having to restart the tablet drivers most of the time when I move between having the laptop docked with the big screen and big tablet on the desk, and taking it out to a cafe or the park and using the smaller tablet that lives in my laptop bag.