How does the US federal govt fund itself?

It is not with your taxes. Your taxes are not funding the actual functions of the US federal govt.

The real problem is not that the taxes are high, the problem is that the high taxes are not actually funding the govt.

Who is financing the govt?

Govt is financed by selling Treasury Bonds. Paper

Who buys the Treasury Bonds? The Federal Reserve.

How does the Fed buy the bonds? By printing money.

What backing does the Fed have for that money being printed? The Treasury Bonds themselves.

Basically, the govt finances itself by printing money out of thin air.

Someone could ask, if the govt can print unlimited money out of thin air, why do they collect taxes?

The answer is simple and shocking.

The real problem is that you pay high taxes to uphold the illusion that you are funding the govt, when you are really not.

The govt is funded by money printing, paper backed with paper.

A bubble that will inevitably burst.

This is the greatest fraud perpetrated on Americans, on all of humanity.