People used to work much harder than they do today. Also, my working class friends are much more sexually active than the cushy office job university degree ones.
This has zero sum written all over it. And yet, it might be true.
The industrial revolution created unusual economic conditions that evened out socioeconomic inequalities. The socioeconomic inequality that existed before then is probably a more nature state for societies to tend towards. Over time the inequality will eventually be restored.