I think this is part of a long term development where technology and globalization slowly erode workers bargaining power. Basically you only build a factory in the US if you can keep labour costs low enough and the manufacturing automated enough so that you can still compete with other manufacturing hubs.
Other countries in the world have manage to keep workers bargaining power in the face of globalization and technological progress.
I think in the case of US literally killing workers and union people is a huge part of why US workers lack power and why US unions are so impotent.[0]
[0] see Battle of Blair Mountain and what work Pinkerton mainly did from its founding to WW2, as examples.
The longer graph (starting at 1947) shows the shift in 2001 on more startlingly
https://fred.stlouisfed.org/series/PRS85006173
Corporate profit vs Labor income divergence (only up to 2018)
https://fredblog.stlouisfed.org/2018/08/corporate-profits-ve...