If you think it is all about "having a crack at American wealth", you are falling into Trump's trap.
For example, the major issue for Japan is they not only are heavily dependent on the US for defence - Japan is full of US military bases, and it has been that way since the ending of WWII. It happens with Germany, too; that's the main reason they are always the last of the main countries to say 'no' to Trump on the EU. The nuclear shield is a very important factor to all NATO allies.
The economy is very important, too. But it goes two ways: US economy would go to hell if all its allies were to broke commerce with it; starting by big tech.
The rest of the world started putting up with Trump craziness hoping it were like the flu and would pass. Besides, cutting ties with the US takes time. Now, they are becoming aware that it's the way things are now, and they have to say no to his nonsense.
Trump have been bluffing all this time, and people is starting to call him on them and isolating him.
The US became a superpower by creating a global network of alliances, and Trump is demolishing them just when the US need for it is more dire.
Well, if the US wants to become a has-been, it's their problem. It's going to take a long time and a lot of effort for us to cut ties with it, but clearly we have no choice anymore.
And don't even doubt we are doing it.