Re (1), I agree there are desirable properties of a less-concentrated economy where every industry isn't controlled by 4 companies and the entire Internet doesn

Re (1), I agree there are desirable properties of a less-concentrated economy where every industry isn't controlled by 4 companies and the entire Internet doesn't run on AWS, I just don't see that as the future. If you agree that technology promotes various kinds of efficiencies (e.g. Uber), then companies who can invest the most in their technology platforms will win the market. Net result: when more investment is required for market participation, capital intensity goes up and you get industry concentration. I think about this a lot as a matter of personal career planning. A lot of my friends work at Apple/Google/facebook and I don't, and I can't help but wonder whether many sectors of the American economy are going to be dominated by megacorps vs. clusters of small (inefficient, but where I prefer working) firms.