I totally agree. In fact, at least on dark mode, I wish they would have used some form of level scaling for the monster hunts and main quests so I can go about enjoying the game while trying to see/do everything without worrying about overleveling content.
I don't think over-leveling will make it so that when you return to earlier areas you'll completely squash the enemy. CDPR mentioned that since there isn't level scaling, enemy numbers would scale with your level. E.g. you're level 1, and go up against three wolves in a swamp. At level 35, when you return to the swamp you will find much more than 3 wolves waiting for you. At least I think that's how it works.
So Dark mode would probably mean getting swarmed with more wolves, maybe? Possibly.