There's been another major shift as well. This [1] graph is critical. There were more self employed workers in the US in 1948 than there are today. The population since then has increased by more than 220%. And the trend increases the further back you go. I mention 1948 only because that's as far back as FRED's data goes! The US used to be a land largely driven by self employment.

We had large numbers of mostly independent economic centers populated with local businesses owned and operated by local individuals. In many ways it's something akin to what you can find in many parts of the developing world today. And it's awesome. But as the economy 'globalized' we've reached a point such that an urban business streetscape in California can very often look effectively identical, in terms of businesses in operation, to one all the way on the other side of the country in New York. You're never going to have anything even vaguely resembling economic equality when a handful of companies control immense amounts of the entire economy.

This also distorts governmental systems since extensive wealth means the reach of companies is practically unlimited. Civil servant versus a company sitting on billions of dollars with international connections spanning the entire globe and the best legal and public relations teams that money can buy? That's not even David vs Goliath, that's ant vs foot.

[1] - https://fred.stlouisfed.org/series/LNS12027714