> Given/family removes ambiguity for a larger number of humans than first/last,
I dunno. The former places the cognitive load on the user. The latter places no additional cognitive load on either party.
After all, what exactly do you mean by "Family Name" and how sure are you that meaning you have is shared by even a significant minority of cultures and people? How many countries have passports that label each name in the name field as a "given" name or a "family name"? How many countries have their revenue service care about whether a "given" name is to be used or a "family" name?
OTOH, to figure out which name is first and which name is last, all the user has to do is look at their ID, which they have presumably seen thousands of times already.
First/last at least has the benefit that, to the user filling in the form, they don't have to think about it - the first name on the ID goes first, the last name on their ID goes last. They can leave out anything in the middle because the form didn't ask them for it!
The problem isn't the NAME, the problem is the addressing of that person which can be only be solved by by adding a field for addressing, and where it can't be solved (titles, honorifics, etc), then given/family name won't solve it either.