Mechanization of farming removed the need for millions of farm workers in the early 20th century. Yet the world population rose rapidly after that, and most of the people still had jobs.

While the world population growth rate has to come down significantly, the larger problem has been that the least capable people are more likely to become parents. In Canada and the US, the teenage pregnancy rate is two to eight times the rate in European countries. Those kids will likely not do too well in the future. 42 percent of children born in the US are to single mothers. They are likely to drop out of school, become career criminals, never go to college, never have well paying jobs, etc