I keep mine pretty short and have been writing them up bullet-style in org-mode for like 15 years. I can scan back over the entire year when I need to deal with my annual review and I don't think I spend more than 5 minutes on this in any given week. Converting from my notes to something I would deliver to someone else might take a few minutes of formatting since I tend to write in full sentences as-is. I can't imagine turning to an AI tool for this shit.