At the time of the Debian debate around systemd it was already very clear that systemd was not just an init system. The systemd website at that time already men

At the time of the Debian debate around systemd it was already very clear that systemd was not just an init system. The systemd website at that time already mentioned it to be "basic building block for Linux". People just pretending it is or only should be an init system was one of the annoying things about the discussion; people only compared the init system part of things and ignored that systemd offered more to developers. Any additional functionality was "not to be used" or "developers should offer alternatives". That wasn't very realistic then and now.