This has worked out pretty well so far, but it seems that according to reports, this seems to have run into an issue with the iPhone X and in particular the phone’s new security feature: Face ID. Users are reporting that they are unable to authorize family purchases using Face ID, whereas in the past they were able to use Touch ID.
Apple has yet to comment on the reason behind this, but ArsTechnica has noted that it could be due to security concerns. When Apple announced Face ID, they also announced a small caveat which is that in some instances, Face ID could fail when it comes to telling twins apart, or family members that bear a strong resemblance to each other, an issue that has actually been proven true before.
It is possible that because of this, Apple has disabled Face ID for authorizing family purchases to avoid issues like that from cropping up in the future. It’s not necessarily a huge deal, but having to enter your password everytime can get a bit tedious. We’re not sure if there are plans to address this in the future, but for now it’s something users with Family Sharing setup will want to take note of.