Not using systemd would have made them irrelevant.
Not that this isn't going to happen anyway, as RedHat absorbs more and more of the Linux-world and it will be increasingly difficult to do anything on Linux "un-RedHat-edly" in the coming years.
As such it has to be seen how much of a differentiation-factor an installer and some default-settings are - together with the complete lack of any kind of enterprise-features that RedHat offers. Because that's what I think Debian et.al are going to end-up being. Because I believe they're even going to adopt the package-format (RPM) and the installer.
If I need something without systemd, I just use FreeBSD. It doesn't do some things, but what it does, it does it very, very well.