systemd is a psyop from some years ago where the NSA, through their proxy RedHat, tried to force every distro (and even the kernel, before Linus smacked them down) to run a certain giant, glitchy, bug-ridden, insecure pile of shit as the general core of the OS. They almost succeeded, except that the madlads at Gentoo made a bunch of shims around important things that allow you to still run non- NSA RedHat software as the core. The other non-systemd distros use these shims.