The problem is that for many (smaller) countries, it's a race to the bottom. They want to attract companies that are huge compared to their "native" GDP or production capabilities, collect a little bit of tax from them, and maybe earn a whole lot more by creating (or maintaining) a financial services industry in their country.

It's hard to stop those countries from doing so, in the current framework of international trade and business. I don't know if a treaty limiting this kind of stuff is in the cards for the near future. And if it is, I'm not sure it would be signed or ratified by financial safe haven countries like Luxemburg, the Seychelles, Monaco or Belize.