i think this!! i feel like all the people in this have a set dialogue when they're “broken” broken as in not being an active player in the game (not having a running casette) that perhaps their dialogue is restricted to their first life’s dialogue. thats why it even seems like the “playable characters” are npc because they literally are at the moment when their casettes arent running. yfm?
I wish that they could experiement with another person they think is an npc like they did with bada

I'm totally convinced that the NPCs aren't actually NPCs, either they're players who decided not to play anymore or they're like Bada who gained consciousness like him.