He's a propagandist. What propagandists say should never be taken at face value. That will be my only comment on this.
The Fed Chair is considered by many as the second most powerful position in the United States government.
As much as I would prefect if the federal reserve was part of the government, it isn't. I get your point nonetheless.
The Federal Reserve Banks are not a part of the federal government, but they exist because of an act of Congress.
https://www.stlouisfed.org/in-plain-english/who-owns-the-federal-reserve-banks