It makes sense that we don’t elect a fed chairmen, but if the fed chairmen doesn’t report to any elected official then where do they get their authority?

Supreme Court Judges are appointed by elected officials, but then don’t report to anyone. Maybe a fed chairmen is like that? But there is no constitutional office like that. Surely congress can’t make up offices which are then untouchable?

I don’t want trump playing transactional games with the FDA either, but I don’t see how that can be balanced with the powers. He is the chief executive.

I mentioned in another comment that one angle that would make more sense than arguing that agencies are “independent” is to argue that trump is not enforcing the law already written by congress, so taking away the power of the legislature. That seems like a more fruitful take.

The Fed is a bit of an odd duck because it's structured quite a bit differently than most federal agencies.

But sure, Trump could absolutely instruct the FDA to rescind certain drug approvals. There are of course processes that legally need to be followed in order to do that, but he could do it.

> it makes sense that the federal branch that manages interest rates is independent of the president.

You left out who the federal reserve is controlled by. It's not completely independent right? In its current form, it is owned and controlled by regional federal reserves which are controlled by the banks.

You are advocating for the corporate bank control of the money supply (and interest rates). One definition of fascism is the merger of corporate and government power. One sign of oligarchy is when corporations control the regulation of their industry.

"Independent government agencies" is just a code word for industry controlled government agencies (which are a form of fascism or oligarchy).