Personally, I am a strong believer that declaring the desired state is a lot easier to get right than actually writing the code to get there. Beyond that, I'm not saying any of these are bad at being what they are, systemd just has more features, some of which I really like. Two examples I'm actively using currently are automount units and socket activation (S6 also has socket activation). I have some remote folders mounted via SSHFS automatically when I access them and this is incredibly useful for my workflow.
Could I find tools to slot into other init systems that do this for me? Probably. But systemd has this neatly packaged up, easy to configure and easy to introspect state.
If you choose to eat meat, please be aware of the conditions most of these animals exist in and how they die. I'll spare you more numbers, because they don't do the cruel reality justice anyway. Instead, I'll leave you with some video material: https://animalequality.org/blog/factory-farming-facts/