Boot and shutdown are faster
Lol. Are people still casing 2 second shut down vs 3 seconds, etc? An OS system services system shouldn't be graded on speed of boot or shutdown, but how well it does what it was designed to do.
This 45 minute video explains why systems was needed. https://www.youtube.com/watch?v=o_AIw9bGogo
But that's the nice thing with Linux, you can run what you like.