The problem for me is feature creep. Someone may create a facial recognition database for worthy reasons, but once that database is created it doesn't take a lot to allow the usage criteria to change.
In Ireland the government is obsessed with issuing everyone with a "voluntary" Public Services Card, the photo on it being biometric. Officially it is voluntary, but you need one to get many public services, including getting a driving licence or passport - so not really voluntary.
The system has been used to catch a handful of benefits cheats - single numbers - so naturally the government hails it as a major fraud fighting tool.
Now catching benefit fraud is worthy, but where do you stop? You may think the GDPR protects the system from abuse, but that counts for nothing where the authorities pull the crime prevention and detection card. The protections provided by the GDPR can be cancelled out by a court order if Gardai claims it will solve/prevent a crime.
And once that has happened a few times it will start to become normalised and eventually abused. E.G. Applying for a civil service job and being turned down for going on an anti-government rally ten years ago.
If you create something that can be abused, it probably will be abused.