Indeed we need at least 5 man party, being restricted to 4 is suffocating. In DAO you could keep your companions all the time and take them for a quest if you feel like it. But in DOS2 at some point they gone forever, and BG3, for now, resembles DOS2 alot. Why make the player to discard the precious banter options? It's looks like a indirect way to force the player replay the game more times. Personally i can accept 5 man party, but is that such a problem to add one more up to six? Apply to 6 man party some xp penalties, this is not that difficult.
Originally Posted by UnderworldHades
Even if they don't add, wait for full release and then get the mod.

But, the thing is, if that issue left to the modders, rebalancing the whole game for 5 or 6 party will take a while and the result will be imperfect anyway.