I think the biggest barrier for young Americans is getting through the paperwork. The EU doesn't make it easy to immigrate (legally). You generally need an offer of employment in hand.
Same with Brits moving post Brexit vote, finding the German environment difficult to do business in.
Really, Europe needs to be able to capitalise on whatever amount of talent flight from the US happens, instead of … whatever the fuck they are doing currently.
I live there, happy to discuss if there's interest!
Once there I realised it's an amazing place. Lovely people. Peaceful and quiet. Good rule of law and stability combined with kindness (you can trust the police here.) High tech. Beautiful nature. Very clean air. Lots of forest. Big enough to have a big city; small-town living if you want.
It's very business-friendly and I started a company here. Then, married an Estonian, so I guess I'm staying here now :)
Are student exchanges still a thing? Maybe we need more of that.