This game isn't DND, and doesn't have to follow the ruleset and it's their choice. Larian have creative freedom, and after playing DOS2 quite a lot i think they know what they are doing and have faith. Trust the method behind the madness, but understand no matter which way they go, not everyone will be happy and if you come to the game expecting a 1:1 DND clone you've already set yourself up for disappointment.
I am going to disagree, they are marketing this as Balder Gate 3, If what they wanted is to ignore the D&D 5e rules, they should have made DOS: 3
I can never understand why people license a ruleset then choose to ignore that. It's not like they are getting to use D&D 5e for free.
For people stating you can never use a Pen & Paper rule set for a CRPG, go look at Pathfinder Kingmaker, they seemed able to use the rules as written.
BG3 seems like a game with way too many house rules. That OK if that what you want but since this is the first D&D 5e CRPG, I would rather be be more core rules and not homebrewed everything.