All right, let's say that the current war isn't legal, and neither was Korea, Viet Nam, Grenada, Kosovo, Iraq, Afghanistan, or Libya. It's not what the Constitution says, but it's been that way for a long time, across multiple presidents of both parties.

The current setup has gone from "only Congress can declare war, requiring a majority of Congress" to "Congress has to pass a War Powers resolution to stop the president from going to war, with enough of a majority that they can override a presidential veto". That is a massively different standard, and was done without amending the Constitution.

So I agree with you. Just don't try to make this something special to Trump, because it's not.