1) The distribution of income has been different over time.
2) If it had been pegged at 70's levels, and wealth generation had been unaffected, incomes would have grown more.
3) But this hypothetical didn't happen.
4) You're being robbed by the enemies of the proletariat.
Also, the data on offer strike me as odd. There has been far more than 8% wage growth since the 70s. This Pew Trends article, which controls for factors like household size, indicates that household income has risen 49% since 1970. Note that incomes have risen significantly since 1990, even as the number of dual income households has remained flat during that period. 
"Meanwhile, wage gains have gone largely to the highest earners."
While I think it's important to distinguish between wages and total earnings, it's also important to differentiate between earnings and purchasing power. The fact that benefits have increased over time won't mean much to the average American if that increase simply reflects a corresponding increase in the cost of healthcare, for example.
In my view, the important question to ask isn't whether median earnings have been completely stagnant over recent decades (i.e. 0.00% growth in real terms), but whether increasing inequality represents some sort of structural change. Thinking in those terms, the range of varying estimates regarding the change in median earnings over recent decades seems relatively small and insignificant when compared to the larger economic picture.
Also, it is not just the home of Bezos and Gates, but multiple other cities according to this audit released by SDOT on 09/11/2020: http://www.seattle.gov/Documents/Departments/CityAuditor/aud...
(Poor bridge conditions: Chicago 14%, Pittsburgh 13%, Seattle 6%, Minneapolis 5%, DC 4%, and Portland 3%)
I'm curious if there will be room for increased automation in these abusive manual labor areas in logistics. Warehouse work, truck driving etc. If these could be automated, then the workers would no longer be subject to the horrible abuse we read about. Amazon and other I could imagine leading some of these efforts eventually.
Not sure however that moves to reduce manual labor will reduce inequality, the person who owns the equipment that replaces 100 workers may take the profits from that ownership.
Seems crazy to me.
Seems like because productivity increased and ease of business has increased more people should be creating businesses since you need less workers to run your business. This also includes the fact by their own admission because the rich can't just store this money most just goes into reinvestment anyway.
So a lot of things may be keep workers from trying but it isn't capital.
The workers doesn't get more of a business for the same reason you don't get a better grade cause you peer got a better grade. The workers didn't supply more labor, but the owner supplied more ideas, better organization, and better intuition. None of bezo's automation ideas has anything to do with workers.
And starting an (ambitious) startup is more risky and is more luck dependent that starting an old style business franchise, or most company in the 80's, which make having capital even more important.
This is more risky, but with more extreme result: you can get much bigger much faster, with network effect, putting the company and its CEO in a more dominant position... We are more in a winner takes all economy, with more losers.
"None of bezo's automation ideas has anything to do with workers" ; without employees, without their work creativity innovation, Bezos would be poor...
The increase of productivity of a company is the consequence of what did the company. And the company is its workers, and its shareholders. Why the workers - that generates ideas, put them in place, make the company running - should have now a smaller part of the productivity gain than before ? (And before automation was big too)
entrepreneurs without workers are just some guy in a room with an "idea"
at some point, the distribution and sharing of the profit becomes unfair (workers also risk a lot too, as they can be fired at-will, and loose thier livelyhood at any time at the whim of the owner) and this is the fundamental problem we are facing i think
The fact is thats exactly what a price or wage is. Fideling with prices because you personally don't like the number two people determined what a worker is worth typically ends in disaster. No matter who it is who trying to price adjust they are usually to ignorant of all parts of the business the to know enough to pick a correct wage or price for labor.