If you've ever been to a really large American city, you'll notice all the logos of the large Swiss banks on big tall shiny office towers. The USA said that if they want to keep doing that, then they have to follow American laws. The Swiss banks decided that running their businesses in America was more profitable than secrecy.

"Follow our laws or get out" is not even remotely controversial.

This sounds like you think this was a bad thing. But a not insignificant amount of swiss bank holdings, and profit, stemmed directly from dormant accounts of holocaust victims, purposely withheld from their heirs under the guise of "privacy"; and from plunder deals with the Nazis.