> There is no "turtles" issue here. Pid 1 is special - if it dies, the system panics. It is good design to keep pid 1 as simple as possible and put the complex job logic in a sub-process. There are only two things on unix which init must do: reap any children it inherits, and start something else to do the heavy lifting.

If the kernel fucks up the system dies and the kernel is much larger than systemd. Either way most of systemd's functionality is in other subprocesses.