Regulation of the cryptocurrency space, for example, such that huge amounts of funds can't be kept and moved anonymously and without consideration of (for instance) local taxes in these countries the rich shop between.

Those who do so must be held to the same standards as those already resident.

In the UK recently we have seen (yet another) backlash against this in the form of the outcry against the wife of the Chancellor of the Exchequer, who was using "non-Domiciled" status to avoid masses of tax, despite having been resident in the country for multiple years.

I've no issue with people moving around, but moving around specifically to avoid contributing to the country you're actually residing in needs to be ended, and regulating cryptocurrency may have to be part of that.