America is a dog-eatdog country. Technologically it is behind both the UK and the EU. Most people who move there are people from the third world. Any first world country is better than the third world.
I have lived and worked on three continents and in six countries, plus I have traveled a lot further. America is living on memories, and its people have been brainwashed. Read Umair Haque on Medium.
I finally left in 2014. I worked in Scotland for a while. Then I lived in Spain. Then I went back to South Africa. Right now, I am lying in bed in a hotel room in Johannesburg. Tomorrow I relocate to Germany.
My point is I think I have a fair idea of which countries are good to live in and which are not.