I don’t think ACNH is more mature than Sims but I think it does a better job at social simulation even if the components are vastly different. In Sims 4 being mean to another Sim in the short term will lower your relationship score but tomorrow those Sims will not remember that interaction and they won’t be angry about that specific interaction ever again. In AC you can’t really be mean to your neighbors but you can do things that will make them unhappy; and unlike Sims 4 there are repercussions for that since they will move away from your island if they are unhappy, and they will not try to talk to you or give you gifts.
So no Ac isn’t more mature than Sims, or even as complex, but what it offers is excellent. Even a family friendly nintendo game isn’t blind to the fact actions have consequences, even if they are relatively minor. Sims 4 just eliminates a lot of that to make a perpetually happy gameplay experience regardless of the actions of the player.
