systemd isn't an init system and doesn't pretend to be one [note] - it's OS middleware with ambitions to becoming a distro unto itself. The systemd project assumes responsibility for numerous aspects of the system that have no technical justification for being under the same project umbrella. You might like systemd-homed, for instance, but it doesn't really have anything to do with the functions of init. Calling it an "init system" is like calling KDE a "window manager".
[note] It describes itself as "a suite of basic building blocks for a Linux system" - although in my opinion that implies more modularity than it posesses.
[note] It describes itself as "a suite of basic building blocks for a Linux system" - although in my opinion that implies more modularity than it posesses.