NRI accounts are different in that they're localized. You don't have UBS in Switzerland asking me if I'm an Indian citizen or resident, like they do for the US.
Sure, as it is in their purview within India. But does UBS or Santander ask their clients in Europe if they're specifically an Indian citizen or resident? Does RBS send a form to a prospective client asking them to explicitly check off if they're a citizen/resident of India or China or wherever?
My point is that the US gov’t asking US banks to verify citizenship/residency of account holders in the US is not that unusual, if looking at the norm internationally. What is your point?
My point is and always was about US government rules forcing foreign banks in third countries to check for US citizenship and residency specifically. Otherwise citizenship checks have always been a thing everywhere. But in order to comply with the US rules, banks have to maintain a separate documented US FATCA section altogether in their enrollment process, even if they are in some unrelated third country.