UI and Party controls hardly has anything to do with DnD 5e though, you are muddling together two topics I feel.
I totally agree that Larian needs to read the Players Handbook again, and all the spell rules, and make the game like that first, then see where they can add the "Larian flair". While I think the game feels like DnD and not DOS2, the game feels like it was adapted from DOS2, and they haven't adapted all the functionality yet.