(Work In Progress)
There are some good things about systemd.
systemd will monitor and, if required, restart your processes in quite a sensible manner. Your traditional
/etc/init.d/ scripts couldn't ever do that, or at least not without some serious help from the application itself. systemd can launch processes, track the main process and/or its children, monitor and even restart them if required.
Many tools have been sold for serious money claiming to be credible enterprise High Availability solutions with worse functionality than systemd in this regard.
Something I came up with recently (mid-2018), is that you can use a systemd service to update a message on the console, such as when the machine's IP address changes.
There's always more ... There must be more good stuff to say. I will find some more. Honestly.