Throughout the movie, camera captures passing people who glance at the boy in rags and just go on their way.
The electricity and water bills don't get paid so they stop supplying the apartment. But the few adults who do know this never ask WHY. Even though it was apparent it was not an empty place.
The apartment manager - she carries around her dog, seems to be a good pet owner. She noticed the trashed apartment when she visited the apartment to ask about overdue rent, where she was only told their mother was working away from home. So she just walks away without any more questions. It's not that she's a bad person - she's what many consider consider normal, gentle, pleasant, even kind. Pointing out 'the bad', that's not the point.
Everyone knows something is wrong with the boy. They just don't care, just so focused on their own life, which is normal. There's nothing morally wrong with that.
Some adults give the boy some help. Food, friendliness, a bit of spending money. But nobody goes one step further outside their comfort zone.
This movie is about people, strangers. We don't care for people we don't know - even if we 'know' them. Of course, it is natural and normal to be focused on our own lives. What if, us people in general, just look around ourselves once in a while? Stepping outside our comfort zone, just a bit further, even if there is nothing of benefit or even 'damage' - this includes simply spending our time on things we're not interested in, spending energy, etc.
Nobody knows? Everybody knows.
also now im sad so im going to listen to despacito