Now that I DO know what your complaint is, your comment about single-player games having to... put up with, I guess... multiplayer systems makes a lot more sense, but it's just super easy to avoid. Like, the problem you have is a problem I didn't even encounter in my playthrough, because I just... didn't do that.
No, it's actually not that simple. It's easy to say "just don't do it" from the offset but often such a comment just neglects player psychology (which means: how other people are wired). Many gamers, especially many RPG-gamers, suffer from a certain form of fear that they don't get the most or enough out of the game. So they try everyting in the game, they explore the whole map, talk with everybody, do every quest, open every chest, pick every flower. I know that feeling. The point is that I find it tiresome and stupid to read the same dialogue four times in a row - but at the same time I fear that I miss something if I didn't. You might call me stupid or weak but that's how psychology works and that's why good game designers design systems in a way that focus (and limit) the experience to its best possible implementation. The very concept of "focus" is that you only implement stuff that is great - and cut out everything else. So even people who want to see every inch of your game have a great time. But with this repetitive group dialogue in place for SP that's imo not the case anymore. Something that is recommended to be avoided should be just cut or changed, that's basic game design philosophy.
Well, I can see why devs wanted to make 4 companions as protagonists - that way in case other players join in and turn it into MP session they all can initiate conversations. It's why DOS1 had 2 protagonists - it was a 2-player coop. And since devs made DOS2 a 4-player coop I don't think 4x samey conversations with npcs are gonna go away.
My suggestions in the first post in this thread are exactly made for this case, with 4-player coop in place. They wouldn't require a vastly different system, actually just some minor adjustments and limitations.