>>105768756
The actual tiers:

>The beating heart of Linux (in terms of contributions and influence)
Red Hat (Fedora, CentOS Stream, RHEL)
SUSE (Tumbleweed, SLE, Leap)
Debian
Arch
>A somewhat consequential enterprise
Canonical (Ubuntu)
>Honorable mentions
Slackware
Gentoo

Literally everything else is defunct, transient, niche or irrelevant.