Basically the worst thing you can do for society and your kids is to be a single mother; by largely every metric possible the child comes off worse - salary, crime rate, ability to hold down a job, education level, poverty etc.
70% of runaways, 70% of juvenile delinquents, and 70% of Child murderers, come from single mother homes. Richard E. Redding, “It’s Really About Sex”, Duke Univ. Journal of Gender Law and Policy, Jan.1, 2008
63% of all youth suicides, 70% of all teen pregnancies, 71% of all adolescent chemical/substance abusers, 80% of all prison inmates, and 90% of all homeless and runaway children, came from single mother homes. Bob Ray Sanders, “Hey Y’all, Let’s Fill The Hall (Of Fame), Ft. Worth Star Telegram, Oct.28,2007 Mona Charen, “More Good News Than Bad?”, Washington Times, Mar.16, 2001 (citing Bill Bennett, “The Index of Leading Cultural Indicators: American society at the end of the 20th Century., New York, Broadway Books, 1994)
Children brought up in single mother homes are: 5 times more likely to commit suicide, 9 times more likely to drop out of high school, 10 times more likely to abuse chemical substances, 14 times more likely to commit rape, 20 times more likely to end up in prison, 32 times more likely to run away from home. Chuck Eddy, “The Daddy Shady Show”, Village Voice, Dec. 31, 2002
etc. etc. etc.
You'll find plenty of news articles by Jezebel and the like (who want to push the "you go girl" narrative as heavily as they can because that's basically their only market) trying to say that this isn't the case; but once you dive into some good ol sociology statistics and studies you find out that there really is a huge correlation.
Now, obviously being a single mother itself is not causing this to happen; but the side effects of being a single mother such as children missing out on strong masculine role models, reduced total income, perhaps the effect on their relationships from seeing a dysfunctional relationship as their "default status" and whatever other issues you can think of are the causative factors.