Perhaps you have not seen what Trump and his administration is doing, but I will explain it to you, in case you don't understand the mindset or the plan Trump may have on his head for this term.
All this is about pushing constitutional boundaries until the extrem, to see how far Trump and his team can get with whatever they want.
Keep in mind the supreme court has already pulled the President of the United States is pretty much inmune to prosecution for whatever he does, as long as it is done as part of his duties, basically giving Trump a get our of jail for four years or even more.

Also, the supreme court is obviously sided by Republicans and with the agenda of Trump, so even if the case of Trump wanting to remove the chairman of the FED was elevated to the SCOTUS, there is a chance they would mess with the separation of power and allow Trump to remove him from his position. He wants to be as authoritarian as possible.