I can just say that Sikh refugees initially left Afghanistan en masse in 1992. They tried to settle in India at that time. They returned en masse again because there were no prospects for them there.
The situation has seriously deteriorated since 1992. Currently, there are no prospects for them. For example, the family I mentioned can't get health care for their daughter, so they have to go back to Afghanistan to go to a hospital. They don't feel safe there, so they have to come back to Delhi. It's just a really bad situation.