I guess I sort of have this issue because I just don't play a lot of games. I usually finish the story, but I hardly have patience for post-game stuff.
Case in point, Pokemon Sword. I'm on the Champ, but all my mons are like 10 levels under, so it's just hard to overcome the barrier (yes, I rushed to the end, it's partially my fault, lol). I know I can beat him if I spend like an hour grinding max raids, but I'm just too lazy to do it at this point.
I don't have games I can't beat though, just unfinished ones xP 99% of the time i'm just too lazy to get back to it.