I do know that my card number has 16 digits, the last being a check digit.
https://www.creditcardvalidator.org/visa/regions/410063
Yeah, so? So you want the OS to block all 16 digit numbers that happen hit the checksum? What if they application has broken up the entry into blocks so it’s not A 16 digit number? The fact of the matter is computers are for data processing. And a significant chunk of the data we process is financial, that what moves our world. Demanding the OS not allow the input of financial data is demanding the OS not be useful.