Cause there's nothing higher than the highest. Levelscaling games are usually well-known for being utmost broken.

Also known as "feeling like a real world" rather than your personal playground. If that's a waste, then so be it. I personally feel the entire game called Oblivion a "wasted content"

If there's no respawning, there's also no need for levelscaling. You can just handcraft all enemies you encounter, and then balance XP on that allowing people a perfect progression. See; This game. Auto-systems that do levelscaling suck in comparison to it, *always*

True, extreme HP bloat doesn't always have to do with levelscaling. But it generally does, as it does with levelbloat. HP's do seem to increase rather rapidly in D:OS too, but I've seen enough levelscaling systems (like Dragon Age: Origins) that HP-bloat can be much, much worse. And I don't want that.

Nope, but after 23, there's 24 and 25 and there are new enemies to find, and old enemies to be crushed.
But in your levelscaled game the joy of new enemies is gone (since they're just your level) and old enemies are upscaled so you don't feel like you made any progression at all. And you get into a stale deadlock of 'what am I doing all this for'...
A good smashing of low enemies can remember a player exactly how much he's become better, that's fun, that makes you feel good. If that's taken away due to levelscaling... that feeling will never be called upon. And it will make the game weaker for it.
You may not realise that, but I have often enough, and thus don't want this game, this callback to good old times, to be tainted by the modern poison that made us back old-school kickstarters im the first place!