Western Europe is the most deep seated Antisemitism anywhere. Even Germany – it was only for a few short years. England alone has basically created the situation, with a little help from France, of the disaster what we now have in the Middle East. They alone decided to ignore the Balfour declartion of the League of Nations. They and a little bit France have created all these enemy Arab states that surround Israel today. Read from Time Immermorial to learn about the history. Why do the Jews love it there as opposed to anywhere else? Probably because of Gashmius. A lot probably have good businesses there, just like why Yidden in America love it here.
As far as Frumkeit, nowadays most of the world is Democratic, so you can be as Frum as you want almost anywhere in the world!