"There's also no reason to assume that tax money goes from wealthy pockets to poor ones directly. The government can build infrastructure (which they do a lot more of than private industry), fund R&D, etc. Individuals could also invest their money into funds that fuel R&D, fund startups, etc. It's incorrect to claim that only the wealthy invest."

And there are some project that only the government can take on due to how long cost recoup would be or the risk levels (Space, Internet...) but those things fund high paying jobs.