The problem with boycotting is that it requires A LOT of people to care. I doubt boycotting alone does much, unless usa keeps getting worse and more people start to care. But maybe Europe can at least become motivated enough to make it's own alternatives for things that usa currently has monopolies on. If we just look at it as a boycott, it's not much, but perhaps this anti-usa sentiment can wake Europeans up at least to come up with some better alternatives.

Given that the regime is corrupt billionaires, crashing the economy to punish them is not that terrible of an idea. It won't take much to push the U.S. into a depression. Everything is setup for one: Massive wealth inequality, deregulation, corruption at the highest levels, government agencies losing functions, international trade wars, etc.

The political changes that made America the power it is was in response to the 1929 depression. Massive government restructuring, creation and expansion of social programs, unionization, infrastructure construction, high taxes on extreme wealth, antitrust regulation and enforcement etc. historians often quote that WW2 was what brought America out of the depression, but it's really not true. It sped up the processes that had been building for 10 years under FDR.

That would already be huge if the idea that depending on a foreign nation, no matter how "friendly" it claims to be, only really makes if incentives for the two nations align naturally became more wide-spread among EU governments and organizations.