That's a myth, all the breathless reporting of an "exodus of millionaires" comes from one very dodgy report.

Of course, the narrative suits the wealthy owners of the media, so the story gets repeated anyway.

https://www.newstatesman.com/politics/2025/07/the-british-we...

The outcome is not as clear as you make it to be. The Norwegian wealth tax hike resulted in a loss of about $600mn of tax revenue. We will see at which point the british will end up on the laffer curve.