If the "competitive jurisdiction" allows people to "move their finances" there without actually living or doing real business there, then that "jurisdiction" is in fact a parasite.
“The strong do what they will and the weak suffer what they must.”
The US or other Great Powers can force less powerful countries to do what they want, when they want to. If that’s protecting the holdings of US companies in Latin America or dictating the tax policies of other countries the disrespect for other’s sovereignty is the same.
You don't understand how secrecy works. A simple way to evade tax is to set-up a company in the tax heaven and send "fake" bills or loans to the real company. Without cooperation of the tax heaven country there is little the on-shore country can do except to black-list the said tax heaven from the financial market. As it happens special interests groups from the UK opposed a black-list of Isle of Man or Virgin Island.
https://www.theguardian.com/business/2017/dec/05/eu-blacklis...