>previously the main driver of inequality was landholders (nobility)
It again is. Have you not noticed that property prices, share prices and rent keep going up and up?
That's productivity gains being captured.
This fomented the creation of a new nobility driven once again from parasitic wealth extraction.
All automation and productivity improvements are doing is keeping living standards in a relatively stable decline while they keep taking.
Land value tax, property taxes, wealth taxes, building - all of these things would stem the bleeding, apart from the minor issue that they have an absolute stranglehold on government.
From the economic perspective of factors of production (labor, capital, natural resources, tech, entrepreneur), more automation means that the same products need less labor and more capital. That shifts both money and influence away from workers and towards capitalists, so that is a quite direct factor that increases inequality.
I mean, the whole concept of capitalists was only enabled by automation during the industrial revolution; previously the main driver of inequality was landholders (nobility) but automation allowed capitalists to overtake them in wealth.