A game where the enemies scale with you removes the entire reward from doing sidequests. Experience should make you stronger. So when you do sidequests and return to the main quest, you should be powerful. And when you keep playing the main quest, you'll get to the point where enemies become a challenge again.
And scaled trashy parties do not also drain your resources, they also drain the fun. Why should the same party that challenged you at the beginning of the game still be challenging, when you basically became an experienced fighter or mage? That's stupid.
And you should be locked out of regions if you are too weak. In other words, what's even the point of levelling up and gaining experience, if it just becomes just another attack that just looks different?
Well said. Level scaling just makes you feel like you don't progress. Numbers go up, but the level of challenge presented by a type of enemy is exactly the same. Most of the presented challange should be appropriate to a player's expected level at this point of the story, but there should also be fodder encounters and ones where you get your ass handed to you. Then you go back and have sweet revenge on that scary powerful monster. That's progression. And that way the world doesn't feel tailored to you.
Regarding BG3, however: does it really feel like level scaling? I remember the devs saying a definitive "no" to it.
