The Democratic People's Republic of Tankiejerk

Not really. I'm not saying melting pots don't exist elsewhere, nor am I saying that somehow the US matters more because of the ideologies it (barely) holds. I'm just saying that the US is one of the largest melting pots, globally. But the ideas it holds are more important than the nation by far. Those ideas will continue to exist (and find another center) whether or not the US manages to be centered in them - for example, if the US is torn apart in the process of those cultural interactions.

But whether or not you like it - regardless of whether you think it's arrogant, that's the way it is, currently. And if that cultural battleground shifts to some other nation, or some other individual nation becomes comparable (there are plenty of ways that could happen), you'll probably also assert that they overrate their importance. And likely, some of them will, just as plenty of folks in the US do.

Edit: Also note, when I said

Mostly, there's not a good culture of actually facing issues and processing them, anywhere in the world, outside of some spiritual practices. If you're someone who does do that, though, the US is the place to be

..that it's both because this is a cultural battleground, and because the issues manifest here. It's not exactly a "positive" statement.