Well the databases are already there whether we like it or not. Generally, with eIDAS, various websites can use an API to access the identity stored on your ID

Well the databases are already there whether we like it or not. Generally, with eIDAS, various websites can use an API to access the identity stored on your ID (public key) when you allow it. Crucially, every time you want to make a legally binding change or sign a document, you need to ask your ID to use its private key to cryptographically sign it. Typically this operation needs a PIN. Without such a valid signature, you won't be able to use someone's credit line. With a well designed system, the government can provide an API to give institutions/apps unique, but app-specific people identifiers. Those can be trusted to each be tied to a unique person, without making it possible to track the services they use (unlike the easily trackable SSN).