Imagine a painter saying "these software engineers are profoundly stupid, I spent a whole day explaining to one how different color combinations are differently interpreted by different cultures and he still wouldn't get it".
Trump: "Not many people know this, but dumb is spelled with a 'b' "
When a 80 year old "aces" a driving test they still have to take it more times to check for further decline. You only take these tests until you fail them.
A similar thing happened between him and Merkel, when Trump didn't understand that the EU was a unified trading bloc with a common market and that making separate trade agreements with Germany was not possible. Trump allegedly asked Merkel more than 10 times why he could not do that.
I don't think Americans still understand what a laughing stock their president is to the rest of the world. This goes beyond personal sympathies and antipathies; he is objectively a very unintelligent person and his exceptionally poor manners make things only worse.
The US is a very big and diverse place with a lot of different people and perspectives. However, most of us actually do understand what a laughing stock the president is. It’s the response that ends up being what we’re judged upon. The responses that perform insane mental gymnastics to absolve him (such as gp) cast most of us in a bad light as thoughtless parrots. There’s also a big nationalist response that leads people to defend a president that they know is an embarrassment because “USA.” There are also those of us who work in silence to educate and allow the embarrassments to carry on humiliating themselves
And, I don't think that Americans yet understand what leaders elsewhere are incrementally factoring in: this is not a one a one-off event. It happened twice. There is every reason to expect that it can happen again - this is a thing that the USA will do from time to time, and so they cannot be relied upon. Decoupling is the wise direction.
e.g.
"The world's trust in America is collapsing. That has consequences"