

Using Guix SD instead.
Real answer, NixOS is very tied to Systemd (the init part anyways). Removing it would amount to rewriting the entirety of <nixpkgs/nixos>, and writing a bunch of extra service definitions for packages that are only supported on systemd. Also you’ll have to reimplement UserDB (which is what this PR is for) to get GNOME (maybe also KDE?) to work.

In the xdg-desktop-portal PR there is a very interesting discussion about how OS level parental controls probably should work:
Presumably an app would send a list of specific OARS tags (which exist for precisely this purpose) to the OS via xdg-desktop-portal, and the OS would respond by classifying each tag as acceptable or unacceptable. The app then is only responsible for not displaying the unacceptable content, and tweaks to the filters based on jurisdiction and new laws/amendments happens in a clearly defined place which is the portal implementation (which could be in an optional package, e.g.
xdg-desktop-portal-content-controls).Of course that system wouldn’t comply with any of these new laws because they’re just bad. Even ignoring all technical considerations, most of them have a ridiculously broad scope (or large uncertainties). They’re very poor legislative work.