They could have done it using Divinity system and would have been not much different but d&d isn’t just the dices, it’s all the classes, races , sub races, sub classes , spells and so on.
So without all that it would have been very limited as far as gameplay goes, would have been like divinity with just a few classes which are also not that well balanced and just a few races .
If we only talk dices then no dices aren’t needed but the entire d&d thing is critical.
Even without the cinematics BG3 gameplay is a lot more fun and better than divinity
