In my opinion, it’s about both the databases and the hardware. Specifically if/when always-on cameras become socially acceptable to wear in public, then facial databases can be utilised.

Presently, I don’t think it’s socially acceptable to always be pointing a phone’s camera at someone.

I recently discovered shadow tactics which has similar mechanics but with a samurai theme. Quite a cool game.

There is also the more recently released shadow gambit which has a pirate theme.