Is there any evidence of this in the data above (or elsewhere)? Labor productivity is a low degree-of-freedom datapoint and your explanation is indirect and has a lot of degrees of freedom.
My opinion was anecdotal. But I think it could be argued the entire field of economics has a lot of degrees of freedom - which is why they do not have firm conclusions as to the causes of productivity loss in the article.
Edit: also see: https://www.epi.org/productivity-pay-gap/