I agree with that.
In multiplayer mode, I think the game need to incentive cooperation (I think the most of us play that way with friends). The dialogue, the way they are now, tend to make (by gameplay logic) the players to rush to be the first to speak (same for loot btw). I know, a lot of people didn't like the first divinity shifumi but it allowed to interract with the party (which is good) and influence the game, even when you are not the main speaker. I have got the same bad feeling in divinity 2 : played with 3 friends, 3 good guys and one lawful evil. When the baddy of us took the dialogues, there was nothing we could do to stop him or to influence the decision he made. (even if it was 3 against 1. Very frustrating). And sometimes we needed to quit the dialogue to let the man with the higher persuasion check to make him rolling the check. It's a little absurd when you see the party members right near you.
Also, it was said by others but simply show the dice itneraction and result for other players would be nice rather waiting on a frozen cinematics (it would add favorable immersion and comprehension of the action)