The aria speaks of life among the destitute in 19th-century New York City. That time is returning all over this country because women are being forced to have children even if they can't afford them. All "those preaching moral reform" do little or nothing to see that a child that is born is given a chance to lead a self-sustaining, productive life.
My mother was one of those children. Her mother died in rural Colorado during childbirth in the depression, leaving several orphans. The father took off—probably because he was also desperate and couldn't face what life had dealt him. The children were seen standing outside by neighbors passing by who eventually discovered what had happened the next day. Several children were adopted by different families. They moved away and the adoptions were concealed. One brother who remained, went out on his own when he was twelve and ended up being killed in prison at the age of sixteen. The fact she did not know her biological family troubled my mother her entire life.
To find out what the actual statistics are about taking care of children properly in foster care, please visit https://www.ifoster.org/the-facts/. Skimping on children has a far higher cost morally and financially.