I just landed in Madrid, coming from Vienna. It was an international flight, but since it was within the EU, I didn't have to show my ID once. I bought my ticket online, I checked in online. At the security checkpoint, I showed my boarding pass on the phone. When boarding the plane, they scanned the boarding pass on my phone.

I could have just given my phone to someone else to travel.

There's a lot less surveillance of travellers in the EU compared to the US.