And to add on to #3, you might not even remember how the game works. Like obviously movement is easy but you might forget some other important mechanics.

Though sometimes this can be a good thing because you might learn the game better the second time. Like I got stuck on one encounter in Doom Eternal and dropped the game for a while. I came back and loaded my old save but had no idea what I was doing because the gameplay loop is more complicated than "shoot everything and pick up drops". So I started a new save to relearn it and didn't even notice when I passed the point I was stuck on because it wasn't hard at all the second time through.

I might end up doing this with persona 5 royal, too, though I put a lot more hours in to get where I'm stuck at.