There are a great number of studies completing that show that opportunities for upward mobility simply are no longer there for the vast majority.
David Willets summarized and touched on studies done by the Resolution Foundation, and wrote a book on the subject matter extensively, "The Pinch, How the Baby Boomers Stole their children's future".
There's a big difference between living hand to mouth as an individual wage slave, and making enough to be able to support having children, let alone the gross excess of the Zuckerbergs or globalists of the world.