Several friends recently posted copies of what I call The Most Important Graph, showing the fundamental break that happened around 1980 when wage growth stopped tracking with productivity growth. (The pie kept getting bigger, but worker's pay was almost flat.)
Somebody asked for an update beyond 2008 or whenever the graph ended, but I can't remember who. Anyway, here it is...no radical comeback through 2022.
Link here: https://www.epi.org/productivity-pay-gap
The article does an excellent job of highlighting the many factors that go into the split. tl;dr - about 1/3 of it is stockholders getting more profits, and 2/3 is a bigger share of employee pay going to the top tier.