How do you expect people to start businesses, fund massive projects in technology and healthcare? They can't
Okay, setting the rest aside for a moment, you do realize that, on a historical scale, we didn't have billionaires until we had millionaires, right? People funded these "massive projects" before billionaires existed. These billionaires were created by said "massive projects", the billionaires didn't appear first. Yes it's more complicated than that, inflation, blah bah blah, whatever. The point is, society was not built off the back of billionaires, because billionaires didn't exist until very recently.
And second, all that technology and healthcare is meaningless if it's only available to a select few. If you think it eventually filters down to average consumers (not that I deny this happens), you've actually just adopted a trickle down model of innovation.
the USA is to be trusted with all industry then ok I hope you like gun manufacturing.
I'm not a proponent of state-run economies, I just want the US government to have a greater say in it than they do now, because the state is democratically accountable while private industries are only accountable to "market forces". If unionization in the US wasn't as anemic as it is, I would care less about democratizing industries, but, would you look at that, the rich hate unions as well and constantly suppress them. Huh, what a surprise.