Independent FED is definitely important, but independent doesn't mean without any agenda. Sure, no president has any power over FED, that is an awesome thing, and every FED in the whole world should be independent like that.
FED is not exactly independent though. The chair of FED is nominated by the US president and is approved by the Senate. Not to mention that the US President has options to remove the chair even if he can't directly fire him. I don't think we can call it independence.
That option that the US president has to remove the Fed chair is limited, which means that a man like Trump – if there was much for him to do in his power – could have replaced Jerome Powell long ago instead of badmouthing him long ago, as that one is not on the same economic path. By law, Trump can only take action against him if he has done anything based on his own personal interest or is not effective on duty.