Why would someone who has options chose to do business with a country who wants to punish them financially ?
Seen Venezuela lately, should be incredibly wealthy, its a basket case because on political policies, and that meant investment disappeared
I have friends and family who are now Australian citizens because the choice was far better for them and their families.
You want to tax them heavily, they will simply go elsewhere.
The rate of tax has very little to do with how successful and happy a country is.
Look at the Scandinavian countries. Compared to NZ they pay high tax but last time I looked they have stellar rates of pretty much everything.