This is an old argument that's long dead. The bottom line is it's a big deal to uproot your entire life / entire company just to exploit tax loopholes, and the use of tax havens is already so common place that it is unlikely to be exacerbated by additional scrutiny.

The book Taxing the Rich: A History of Fiscal Fairness in the United States and Europe talks a lot on this topic. The authors Kenneth Scheve and David Stasavage defend progressive taxation, and state that the only historically-successful argument for raising taxes on the ultra wealthy has been "conscription of wealth" - The working class were conscripted to fight and die in war while the propertied class were not, so the property of the ultra wealthy was taxed very highly (conscripted) for war efforts.

Today, the world faces numerous crisis, and it is the lower class that will work the hardest and be forced to suffer the most while resolving them. It seems reasonable to me that the wealth of the upper class should likewise be put to use solving these crisis rather than exacerbating them. That's a conscription of wealth I can get behind.