You were defending your friend when what he said was one of the stupidest things I've ever heard in my life. How one gets from "Europe has the most comparable economy to the US since they are also western, developed countries so we might have a similar NRU" to "so you want us to be just like Europe ???", I haven't the faintest idea, especially considering I didn't even mention what I want at all.
They aren't exactly the same - if they were, it'd be no point comparing them; they're the same! Aspects of the countries in Europe, such as the style of their economies, are the most comparable to us out of the whole world. Also, considering all of those countries hold huge dollar reserves, part of the reason our dollar is so immune to inflation is because Europe and Asia hold those reserves. If they dumped them, our dollar would become trash very quickly.
I was never comparing us to individual countries. The total GDP of the EU is larger than the US', but only slightly. We are not exactly the same, but if we want to see where we might go, we have to look at economies that are most similar to ours and Europe fits the bill. There is unfortunately no clone of the US available, so we cannot compare ourselves to them. However, to say that just because we are not exactly the same, we cannot compare ourselves is preposterous.
Economy-wise? Eh. We were a dominating superpower 40 years ago, but we're fading. We'll continue to be a big economy, but we won't be (and I don't think we are even today) exceptional.