Debian, Gentoo, Redhat, FreeBSD, etc all depend on heavily on volunteers to create the packages, manage dependencies, issue security announcements, feed bug reports and patches upstream to developers, etc. I've used Gentoo for a long time and I've watched it struggle in recent years as it loses volunteers. New releases take longer to reach portage, some software never finds its way to portage at all, and I find more and more broken packages. The only Ruby package I install from portage is Ruby itself.
The thing is, every Ruby developer uses RubyGems. There are no volunteers because the developers themselves create the packages for each release. I think this is more sustainable, even if I don't think RubyGems is as good as the packaging tools used by the major distributions.