PS: One thing that is a lot better than in BG1 and BG2 is that combat with low-class characters feels a lot more interesting. Not sure how much of this is because of the ADnD vs DnD5 rules or whether Larian has added some tweaks to the DnD5 rules.
That's entirely on D&D 5e rules. Combat with chars under lvl 5 is essentially 1 mechanic per class, and really boring.
Tabletop suffers from exactly the same issue, even if you use all the extra/optional subclasses and backstories. So does Solasta (the other 5e PC game)