The only time I have used fingerprints for flights is for bag drop. That is, the fingerprint verifies that the same person dropping the bag is the one that later boards the flight. In that scenario the fingerprint is not needed after that, and I'm sure there is no regulatory permission to store biometric data for any longer period of time than necessary, which is only until the plane leaves. I haven't seen these syst…
In which country was that? You mention GDPR, but I've not seen it in the ~10 EU countries I've used airports in in the last few years.
That was Sweden. I googled and it was introduced around 2007 in several airports but I can’t see when it was discontinued but I think it was around a bit into the 10’s at least. It has definitely not been used in the last 5 years in those airports and possibly not even the last 10.