Beg to differ on the Pokemon example, but then again I am a completionist so that type of challenge gives me lots of self satisfaction (plus now I have achievements through RetroAchevements so a little bragging rights). Frankly, things like that should have internal motivation, so literally no reward is fine by me. I'm literally doing a professor oak challenge right now, which is significantly worse, lol.

Where I draw the line is mostly challenges that I just don't see myself being able to accomplish in a given lifetime. Like the Balatro golden chip on every joker is way too RNG and time consuming for me. I also generally prefer not to have to do a speed run, but that's mostly because I have kids now and setting something down without worrying about time is ideal.