it is indeed common for kids to stay with the group like them and is more common now than before. It surely helps kids to stay less affected by bad influence, but it unfortunately leaves remaining Jews without any positive influence. We can’t leave them just to chabad shluchim and”kiruv” professionals.
On a personal level, if someone lost friends due to being more observant, it is also a reflection on someone’s level of observance. A true Torah scholar should cause positive emotions among at least some of their friends at least according to beis Hillel