I don't think the author intends to provide a serious production solution, at least not for now.
Runit tools in busybox - up to the task?
Let's test busybox's runit applets in a hypothetical ;) scenario
when someone needs to stop running, say, systemd on, say, a Fedora machine.
No doubt this will expose various shortcomings.
To me, This just seems like a fun experiment to demonstrate busybox's capabilities.