Game rules are game rules. Sometimes they are not compatible, despite the appreciated effort (and it IS appreciated)
Larian doesn't need to rewrite a system that already works and that they're trying to adapt. Full stop.
Honestly if they bulldozed 5e and replaced it with something that wasn't an imbalanced mess I wouldn't be complaining.
Fallout 3 completely overhauled the series, and besides the weak story it was great. Total War: Warhammer plays absolutely nothing like the tabletop strategy game but is still awesome for what it is.
What we got with BG3 is a half-assed hybrid that captures the worst of both worlds rather than the best. That's what needs addressed.