The drama.
Look up Article II, Section 2, Clause 2 of the Constitution.
Everyone loves to ignore this key part of that...
He shall have power, by and with the advice and consent of the Senate; to make treaties, provided two thirds of the Senators present concur;...
Something that has been very much lacking on this. The representatives of the people and States should be approving this, not just done blindly. I suggest reading Federalist 75.
Also, that skips the point we are making which is the massive extent in which this is being done. Specifically around Tariffs (which are technically different than treaties and should fall under 'taxation' which actually should be going completely through Congress first. He may be using them as a negotiating strategy for a future trade 'treaty' but his is skipping the Constitutional requirement of Congress in this. (Article 1, Section 8, Clause 1).
Also, it is just the fundamental principle of our system how much should fall under such a central planning path such as this. This shouldn't be the federal government's business to promote and pick winners and losers.