@juergen Does it, though?
If I am guaranteed that only the birthday, the age or even only the Boolean answer to “older than X” is transmitted then it follows immediately that it is completely risk-free to offer to do the age verification for others, for friends, for family, for strangers on the Internet for a small fee.
If you want to track abuse, you have to store identifiers.
You want to force users to get the Online-ID functionality and later the EUID just to be able to use the Internet. And you want to force every website to do the quite costly and non-trivial Online-ID integration (remains to be seen if the EUID will be easier with open standards or if it will also be a bureaucratic nightmare). And that all for very little gain.
That's all unacceptable!