Fewer people mean that there is more of everything good to go around. On page 41 of A Farewell to Alms: A Brief Economic History of the World Gregory Clark has a chart that from 1300 to 1485 real wages for building and farm laborers rose dramatically to 1480, and then declined again.---The Rapid Decline of Global Birth Rates---
Charted: The Rapid Decline of Global Birth Rates
For the last 70 years, birth rates for the 49 most populous countries of the world have fallen sharply, heralding an uncertain future.www.visualcapitalist.com
The reason was not a strong labor movement or an increase in labor productivity. The reason was Bubonic Plague, which killed nearly half the European population. With a higher standard of living more people got married. They got married earlier. The average standard of living declined again.