I hear you. Lots of laziness from Larian's side indeed. This is the true reason why we don't have D/N cycle.
There are plenty of solutions.
I completely disagree with your premise. There is nothing lazy about it. It's a question of resource allocation. Someone made the choice to spend the resources that it would take to implement a day/night cycle on other aspects of the game. And I thank them for it. And while my opinion is no more important than yours, it is no less important either.
So since they allocated the resources they did to get us to where we are, what would you cut out of the current game to reallocate for a day/night system? Same goes for people who don't want a static camp or want 6 party members. What are you willing to give up for that? I think a day/night system like #3 would be cool. I think a dynamic camp would be cool. I think 6 party members would be cool. But at what cost? Would I rather see those and only have 4 classes right now? Maybe no subclasses? I don't know what is an apples to apples comparison of resources. But to call it lazy as opposed to a deliberate choice of how to allocate a finite set of resources is absurd.