I agree it would be really great if for coop if the other players votes are more meaningful and final choice is not just what the conversation starter selected. The arguments between the player characters during dos1 were the best moments for us, we constantly tried to charm/persuade/intimidate each other when we did not agree on something in order to convince the other one why we should deal with quests x or y way. It gave our party a unique chemistry.
The rockpaperscissors system worked well in dos1 but there could be other ways fitting style of bg3/dnd more, as others wrote it can be decided via dice roll or persuasion skill checks or something.