The concept of taxes funding federal spending is a two-edged sword for the wealthy. It keeps the little people in their place and preserves the vast wealth gap but it also means that Congress will turn its collective attention to them whenever it needs to spend.
Their wealth has little effect on the overall economy since it mostly remains sequestered away from circulation and doesn’t drive inflation. It is the propensity of the wealthy to exercise control that is dangerous, not their wealth alone. If they didn’t feel the need to influence legislation to protect their wealth they would likely stay out of government to a much greater degree but their desire to shape the culture would always be a threat. The characteristics they all seem to share are not conducive to a fully functional society.
Once we figure out that we don’t need their money to have nice things we can make them irrelevant and use taxation to punish bad behavior instead of as a funding source. Things that drive inflation could be taxed so heavily that they aren’t worth the effort and we could even cap total wealth accumulation if we wished. It is the people’s money that they use to become wealthy in the first place, so they would have little room to bitch.