the capital/labor class gap increases when total returns on capital investment exceed total wages+redistribution to the labor class, and the gap shrinks when that's reversed. the market ~controls the capital gains and labor wages knobs, and society decides where to set the redistribution knob.
the article investigating the post-covid drop and concluding that it's normal is an interesting rhetorical device. on one hand, relief that nothing crazy is happening. on the other hand, disappointment that we've accepted a growing inequality gap as normal. the gap was already at a post-war max going into covid, the floor gave out 20 years earlier and covid was just gas on the fire.
advancements in automation and tax codes that benefit capex over payroll will continue to incentivize business to shift budgets from labor to robots.