I hope this works out. It seems helpful but we can’t even get a lot of web sites to format their user/password fields or address fields to work correctly with password managers and autofill. This has to be more complicated than that.
If enough websites have duplicate functionality it should most likely be implemented in the browser.
Let Mozilla or Alphabet define an API for country addresses and let national registers implement it.
Having some tiny website buy a db with an outdated version of ALL the worlds addresses is terrible. People with new addresses buy a disproportionate amount of stuff.