These? Don't exist.
Systemd is the most feature complete and it's not even close. Runit has nothing to offer that systemd cannot provide, but the inverse isn't even close to being true.
You have to realize these distros are usually general purpose who serve A LOT of use cases. They target desktops, home servers, professional servers, enterprise. That's a lot of different users with a lot of different needs.
Now you may think some of those needs/features are stupid, unnecessary, or (everyone's favorite word) "bloat". But the reality is some people rely on them so they push for them to be added.
Now you have a problem where you need all these features. Distros can choose to maintain 2 init systems (hard) or just go with the one that provides features. The choice is, and was, obvious.
> EEE
Oh, drop the delusion. Systemd didn't do anything, the distros chose this and they chose it because it's the best. If that makes you uncomfortable I don't care - in fact nobody cares.
Well, it's quite simple; users who didn't want systemd had it added to their systems, and were told things like
> you're 100% free to maintain your own Alpine distro
by people who pretended that that was practical, or
> just switch to a different one
except then that one also switched to systemd.
> Other init systems are less functional, with less features which some users want.
Yes, that's much of why systemd's EEE has been so effective: Nobody ever comes along and says, "we want a nicer service manager, so we'll adopt runit". They inevitably say, "we want this extensive laundry list of features that happens to exactly match what systemd provides, and nothing else provides this exact list, so obviously we should just adopt systemd". Somehow the fact that users want features systemd lacks never comes up.