It would give an enormous power to who controls this “front page”. This page could restrict any user arbitrarily, lock them out, spy on them, etc. And because this page would be unique, they would have no alternative. This is exactly why federation is a key to freedom.

I can only recommend Guix system 👍

Well, I think that if declarative configuration is what you’re looking for, the GNU Guix distro with its GNU Shepherd init system might be a more pertinent solution than SystemD

Libreboot?! It’s not on Savannah. But perhaps you meant GNU Boot