There is no shortage of older siblings who are tasked with the near-constant care of their younger siblings. This is a familiar dynamic in families where both parents work, and there's no grandparent, aunt, or uncle who lives nearby and is willing to share the babysitting load. Just because many families do it doesn't mean it's right. There's a significant difference between an adult child moving back in with their parents to help care for their younger kids out of genuine desire and doing so because they feel they'll be exiled from the family otherwise. Young adulthood should not be about finishing the family your parents started. Young adults need that time to find themselves and build the life they want; otherwise, they'll end up resenting their parents and feeling stuck in that teenage stage.
Once you're 19, you don't have to do what your parents say anymore. If they have proven to you that they don't respect and care about you, you can go off and do your own thing. But even if you know your parents have wronged you in an unforgivable way, you might still feel the urge to seek their approval. They are your parents, after all. Even if you know that they aren't good people, you might want to win them over by being the best person you can be.
The young man in this story is conflicted about whether to give in to his family's demands or not. He has a pretty good reason not to want to talk to his stepmother again, but is that what he really wants to do? Going no-contact is not as easy as people make it out to be on Reddit.