History shows that if you over tax the wealthy they relocate.
The wealthy like to live in a place that has good public health, a trustworthy police force, a reliable legal system, safe roads, good shops, restaurants and galleries for the WAGs, good schools and universities for the urchins, and a government and gangsters that will probably not steal your money, kill or imprison you. Most of them speak English or other major European languages. For example, many of them have homes in London, or Vail, or Geneva, or Paris.
Surpisingly, the countries with these advantages have found that public services have to be paid for.
Every pound of tax that a billionaire or multinational dodges, is a pound that the honest citizens have to pay, or a pound deducted from public services.
There's a lot to be said for nations co-operating to prevent billionaires and multinationals playing countries off against each other in a Dutch Auction.
if billionaires and multinationals paid their fair share, would we need a 40% tax rate?