The independence of the Fed is key to protecting the dollar, the economy, and price stability. People can trust in the dollar because the Fed will do what needs to be done to control inflation, even if it is painful.
Big things Trump’s economic team wants to do would require great international deals, but those deals are worthless if no one trusts the United States or its president. Trump is so erratic, that no one trusts him. He made the NAFTA 2.0 agreement with Mexico and Canada during his first term, then during his second called it junk and tried to break it. He threatens to take territory from allies and threatens to renege on NATO promises. Countries won’t make the sacrifices of a big Trump-pushed-for-deal when they can’t trust Trump to keep his promises.