When I moved to the UK from Germany in 1986, I did just that. Move. I did not emigrate, because within the EU, people simply move from Frankfurt to London like they move from Manchester to Leeds.
2016 changed all that. For years, people had assumed I had British citizenship. I didn't. Either nationality doesn't matter, then there's no need to change it, or it does matter, then it's not an easy thing to change. I never felt particularly German nor particularly British. I was just me. European, if anything.
Now my Eastern European friends were targeted. There were... there are... more racist attacks on Europeans, if you have a strong accent, you suddenly no longer feel safe. "We didn't mean you!" But you did, you know. You meant people like me, who just moved here to live, to have families, to contribute. To protect myself from having to apply to stay in the country I had spent all my adult life in, and maybe to be refused, I became a British citizen. The day I made a formal promise to this country was the day I felt least British and most German. I became one of you because you have become a threat to me. It was one of the worst days of my life. I'm now one of yours, but I no longer belong.