The problem is that Trump (and acolytes) are convinced the US can do it all single-handedly. The truth is that we are a mighty and powerful nation, but we are still only 25% of the economy, and less than that of military, and less than that of population.

Yes. They're convinced that other countries are absolutely desperate to do business with us - that our economy or businesses or people or what have you are so extraordinary that nations cannot countenance any possible risk to their status, and that they would pay any price at all for access. But as posted on TMF, none of the major economies are rushing in to make a deal. Because they're not willing to pay any price to be part of our world:

yahoo.com - White house pressed fast negotiations

Sure, of course they all had to call up the WH and start discussions. The U.S. blew up a hand grenade in the middle of the global economic system - every government owes it to their citizens to call us up and ask, "Why did you do that and what do you want?" And see if there's a trivial way to make this go away.

But other countries are going to be very loathe to enter into any kind of serious, long-term arrangement that reorders trade with the U.S. without a lot of long, thoughtful review. Especially since they can't really get any assurances from our side that whatever they negotiate would be honored. Since Trump can't be trusted to abide by a trade agreement (even one he negotiated and was approved by Congress, sorry about your USMCA Canada and Mexico) there's little benefit in making significant concessions in order to get anything from us.