There is a detail that makes it possible: the absurd over sharing everywhere. If only everyone did not think to plaster everywhere their face with their selfies and decide to share everything everywhere, then maybe something like this would be a lot harder to implement (if possible on certain cases)
That is for sure a good question, although I would say it would present limitations.
Let’s put it this way: Id photos are very standard. Front facing, until the neck, white lights, white background. Now lets say everyone’s photo got leaked (or used) and the only source of photos for a certain photo is the Id one only. I didn’t study the matching algorithms, but I will say that variation for a certain subject under different circumstances increase the matching possibilities. If by any chance you try to match someone live and the only source would be id photos, my guess is it would present a big error rate. Possibility could be fine tuned, not sure up to how much.
Now lets consider what we have today. For a single person, I will bet there are on average more than 15 photos of themselves somewhere available (for those chronically attached to stuff such as IG of fb) and a lot of the times tagged as well (and manually as well, there was a time on fb this was a big thing). With this amount of comparison points, I would say the matching for sure works a lot better