there is no verification happening though

There is in New York, Brazil, and probably other places too. Attestation is a foot in the door and will become verification when it is shown to be ineffective. And unless the law is defeated, it will provide precedent for further legislative intrusion into personal computing.

First they have to build infrastructure for the future mandatory KYC. So, age field comes first, then comes new Poettering startup to deny you modifications of your Linux, and finally you are not allowed to use a computer unless you present your ID.

Because systemd isn’t an operating system. It’s just providing a mechanism for the OS to store/lookup the user’s birthday. It’s up to individual distros to do the verification (should the law stand and OS vendors choose to comply)