Some of my best friends still hunt and farm for their meat and eggs, and grow vegetable gardens for their vegetables. They'll spend some mornings on their boats fishing... while taking calls and photos on their iPhone.
Technological efficiency in free market capitalism will make many of our current jobs obsolete, but people will keep finding ways to survive, create, and enjoy their life.
There is simply not enough land on the Earth to feed 7 billion people without modern technologies. So only a minority of people can downshift and live simpler life, but not >90% of "useless" population.
As the concentration of power in the hand of few is not proved in a free market (quote me one company that ever got enough capital for mass scale coercion), it has been already been proved in democratic (and non democratic) government.
Large U.S. oil companies have significant influence on the government and many wars were ignited by them in last 20 years.