And SysVInit just works well and it is simply enough. It has much less dependencies than systemd. Do not make unneeded weight on people to learn systemd in addition to shell scripts, if systemd is powerful that also means there is a lot to learn. I really doubt non-standards task can be solved with systemd without shell scripts (or similar), and every serious UNIX admin must know shell programming anyway.
This is like saying "A horse drawn carrage works well enough, why do you
need an airplane".
You need an airplane because Earth is 40,000 km in round and because you have a reason to travel to a distant location. Or just you want to do some sport? But I know my possibilities and I wouldn't spend my money on an airplane just for sport, to produce an airplane you have to take raw materials out of this planet, you have to spend power, human time, make pollution, etc.