If there won't be a callback into governmental database, you can make stuff up as you go with something what resembles correct ID. If there will be callback into gov database, you can just query it and mine valid IDs using gov database as an oracle.

German IDs have cryptographic keys in their chips that make them theoretically unfakeable, so no

Which works only if you have card reader. If you are making a photo for internet service, then how do you read the chip?

phone, the app already exists https://www.ausweisapp.bund.de/

a lot of people still scan their id but theoretically fraud prevention is possible