Best read I have found explaining chart.
Understanding the Historic Divergence Between Productivity and a Typical Worker’s Pay: Why It Matters and Why It’s Real | Economic Policy Institute
Increasing productivity enables an increase in wealth (more goods/services produced per hour=more goods/services available with a given number of work hours). Pay (like any other commodity) is set by supply/demand. If the supply of workers is plentiful, we should expect pay increases to be low. Workers don't automatically get a pay increase because their companies are productive and profitable. If they want to share in that (and the accompanying risk when there are not profits), they need to become owners--buy stock.
Regarding the EPI report--well, consider the source and their viewpoint. There's very little in that report that takes into account true labor force availability and demand (which is the major factor affecting wages--a key item they are supposedly studying). U.S unemployment figures tell us little about the "slack" in the labor force (a better measure is labor force participation, not mentioned by EPI in their report, but nearing historic US lows right now). There are plenty of available people to work in the US for the number of jobs available (esp at low skill levels), that's going to drive down pay. And that's before we consider the inevitable foreign labor market factors.