It's hard to write laws to outlaw them. I mean you can't really outlaw a company shuffling money around to meet their business needs. You also can't write law

It's hard to write laws to outlaw them. I mean you can't really outlaw a company shuffling money around to meet their business needs. You also can't write laws governing another country. So unless there's a big international effort to get all countries to adopt some consistent tax laws, and cut off trade with the ones who don't sign on, there will be some countries who profit from keeping their laws favorable to being tax havens.