Honnestly I'm not interrested in BG3 "because it's a D&D game" but trying to learn what I was talking about here lead me to this conclusion : D&D has a stronger, deeper and more consistent system than the hybrid system we have in BG3.
I don't understand why a video game couldn't have a strong, deep and consistent system and a few "fun" homebrewed additions at the same time.
Again, it's only a matter of balance not to drive players in a way more than in another.
That approach would have required Larian to start with 5E rules, and then modify change those rules, but that's not what happened. They started with DOS, and then tried to add in 5E, found it too difficult and/or didn't really understand 5E rules well enough to balance changes to them, and what we have is the current gobbledygook of DOS with a smattering of 5E.
Technically, from what I remember, Swen mentioned that they started out with very strict rules but internal testing showed that they didn't work well. Believe it or not, it doesn't matter.
Or they just have a really narrow vision on what "works". DOS gameplay doesn't work for me at all, so it's all subjective in the end.
I would argue that BG 1&2 gameplay works, and so does NWN, Pathfinder and Solasta as other implementations of D&D for a CRPG. But based on the changes to D&D rules in BG3 it seems the folks at Larian think only DOS works out of that bunch.
I would say that they are right, at least in a way. They certainly know how to reach more players. If you compare DoS2 sales to its competitors, it doesn't look too cheerful. Overall, DoS2 sold better than most of its direct competitors combined. You can argue whether they were better or worse games than DoS, but it doesn't really matter. If you look at it this way, Larian does know "what works". It is not without reason that WoTC was chosen by Larian and not for example Obsidian, which had to be rescued by Microsoft after the last mishaps.