Systemd is not only more convenient, it's also more simple. Proof? sysvinit's surface is anything you can call. It's internal state is everything on the system

Systemd is not only more convenient, it's also more simple. Proof? sysvinit's surface is anything you can call. It's internal state is everything on the system. Systemd's surface is the (well documented) commands in the systemd unit files. Each unit is pretty much independent, the dependencies are specified and well defined. Their internal state can be examined and explored.