It's dated. Takes too much space and covers too much of the screen. U shape isn't necessary with higher resolution screens. Still, there is some functionality I wish Larian would borrow - or even better, from updated PoE2 design. I doesn't need to look the same. Just let me play the game, without having to spend 10 minutes sorting and assigning skills and items to the hot bar.
The old IE UI was beautiful but does not cut it for modern videogame standards (unless for mobile apps). Not only that, three clicks to cast a spell? the space for multiclass habs was a mess ( cleric-thieves, everyone?), etc.
I think a retro skin would be salvageable, but a game with (somewhat) complex rules needs an UI that handles lot of interact and combat options and also offers info without cover too much screen.
About customization, I prefer just the opposite: I want to be able to customize the bar to my liking for easy access to the skills/spells/items I want.
In games that handle that automatically, like Dragon Age or DoS, my action bar is usually a mess and I like to keep it tidy and functional if possible.
