Yeah, I know the argument...displaced workers will find other work. Yes, that's been happening, at lower and lower and lower pay. Meanwhile, the middle class is rotting from the inside out.
There's an over-focus on unemployment rate and other fluffy metrics (that make politicians look good). And not enough attention to the mental, emotional, educational and financial health of the middle class.
The sociopolitical fabric is already frayed, no one seems committed to mending it. There's a tipping point. There's a breaking point. Past performance is no barometer for future results.
The first[1] shows "Real hourly earnings for production and nonsupervisory employees", while the second[2] shows both the "Civilian Employment-Population Ratio" (in red) and "Wages and salary / GDP" (in blue).
While these don't specifically give much insight into the plight of the middle class, I think a case could be made that as more people entered the workforce, that lead to increased economic growth but proportionally less of that growth was enjoyed by each employee.
[1] https://assets.weforum.org/editor/Xkzpnpz_lnI-0WbTH1LJVUdu3J...
[2] https://upload.wikimedia.org/wikipedia/commons/6/68/Goodwin2...