In 2008 the dollar was historically cheap (70% of current), now it's pretty expensive. This swing is the main driver of this whole thing and means that yes, PPP is superior for looking at growth. Not ideal, but much better.

Cheap imports are great for consumers, but a currency losing 20% certainly doesn't mean its economy has magically contracted 20%. If anything a weakish currency stimulates internal economic activity as it's good for exports.

The US economy is also not nearly "twice that of the EU", in nominal terms either - it's about 50% bigger. The (silly) chart is for the eurozone.

Seriously, the US always had a somewhat bigger/stronger economy, but a cheap dollar at the time made nominal almost equal, which was misleading. Now, the US still has a slightly bigger economy, and has had better growth, while the price of the dollar makes it look like a massive difference, which is also misleading. The true output difference is high single digit. Why are you pretending otherwise?