It is probably more standard than you realize? Quick search shows over 14 million are enrolled in the airport program that requires iris scanning, as well as fingerprints.
Yes, US. And agreed it isn't majority, is why I gave the number. Should have made that clearer.
Probably better to look at passport, if we are only talking about fingerprints. And that is about half of the US? Still not a majority, but I assume a lot of "standard" things aren't majority. I was pointing out that it is getting more widespread.