And 64 years ago, GECOS was released, with a dedicated field for a users real name, location, phone number and email. That was implemented in UNIX shortly after, as a field in /etc/passwd, which means all Linux distros and other UNIX-like OS's like MacOS have and had fields for all of that forever. So if you don't want the option to store personal information in your OS, use TempleOS.
Ah but this is systemd! Your logic and reasoning does not apply here. People just love to look for things to hate about it.
I can only hope that people will someday realize that systemd did nothing more than add a userdb field, symmetric to other, similar, userdb fields, while the distro installers are the components that actually decide wherever you need to enter your data, and more importantly, if that includes an actual verification of that data.
If you want to ensure that real age verification will never be a thing, tell your distro maintainers how you feel about that, participate in relevant discussions about the installer etc. Also, support realistic pushes towards keeping it out. No, a random GitHub user won't be able to maintain a hard Ubuntu fork without systemd. Not even for a day. However, it is possible to maintain a soft fork of the installer, minus age input, including the building infrastructure for release images.
Even if systemd would now remove the BD field, or all user info fields, distro maintainers could and would just switch to another implementation, nullifying any efforts and just worsening the situation.
Shit, just linux.
Use this community for anything related to linux for now, if it gets too huge maybe there will be some sort of meme/gaming/shitpost spinoff. Currently though… go nuts