The way to address wealth inequality is through tax and inheritance reform to shift the incentive system. They way to address political cronyism is political funding reform. Changing the ownership structure of corporations by putting them int eh hands of bureaucrats isn't going to do anything whatever to address either of those issues, in fact it would almost certainly make both of them much worse.
The reason we have billionaires is because these are the people that create tens of thousands of jobs, produce innovative products, provide valuable services. The billionaire owner of a company doesn't have billions of dollars in cash, that wealth is embodied in the value of the jobs and goods and services that make up the companies they control. So if you're going to take that away from them, who do you give it all to? Who gets to decide that?
The fact is capitalism for all it's flaws does work, and compared to the alternative systems that have been tried it's spectacularly successful. Capitalism has raised billions of people worldwide out of poverty, and raised hundreds of millions of people into the middle class. In fact today for the first time in history half the world's population is middle class. These are staggering achievements made possible by unleashing the creative power of individual people exercising straight forward individual economic freedoms. The freedoms that you want to take away.