The second game I ever 100%ed was Arceus and I still can’t stand the thought of picking it up again, years later. The first game was Horizon Zero Dawn, which is still fun.
Oh that's really rare for me, since I'm not a person who can generally do "grindy" parts well if the grind extends past what is clearly the main intent of the game (that is, usually the story).
The last game I 100%ed is Pineapple On Pizza. A free 10 minute game, 20 if you go for all achievements. Says a lot about me I suppose. 😅
However, I do sometimes go after rare achievements because the ideas behind them sound intriguing to me. But I can't be arsed to go for all the other stuff, ingame and external, too. One good example of something I had to do is that the expansion Hate Plus has an achievement that for the longest time would get manually credited by the dev if, at a fitting moment in the story, you bake an actual cake and take a picture with it in front of the monitor at that scene.
Was time to bake something again, anyways. 🎂
You'd probably be able to 100% Turnip Boy Commits Tax Evasion. Only about an hour or two to finish the game, and another 15-30 minutes to figure out the two extra achievements.