The public sector doesn't really have to take risk because it can always raise money at the point of a gun through the tax system, whereas the private sector runs out of money. So I would even be more extreme than you are in the some ways that I'd be agreeing with you, but even more than you just said, which is that the government actually doesn't rely on taxes. It can even just literally print the money. That's what it does when we go to war. In those cases, and this comes back to your previous point about the military industrial complex, they can unlike a family, unlike a household, just create that money.
Economist and author Mariana Mazzucato talks about her book The Value of Everything with EconTalk host Russ Roberts. Mazzucato argues that economists have mismeasured value and have failed to appreciate the role of government as innovator. She argues for a more active role for government in the innovation process and for government to share in revenue proportional to its role in the creation of new technology.