While it's true that a good number of RHEL users don't use EPEL due to the lack of vendor escalation, there are many that do use it. In fact, they tell Red Hat that specific EPEL packages being available in the next version of EPEL block them from migrating to the next major version of RHEL. The feedback finally got loud enough that Red Hat decided to provide headcount to the Community Platform Engineering (CPE) group to create an EPEL team focused on improving EPEL (this is my team at work).
That said, the "vendor escalate-able only" group is large enough that RHEL is significantly underrepresented in EPEL stats. My guess is that somewhere around 40-60% of RHEL customers use EPEL. For RHEL rebuilds, I would guess that it's probably in the high 90% range, so their numbers in EPEL countme stats are probably fairly accurate. CentOS Stream on the other hand is also underrepresented, as we have countme data for both EPEL 9 and CentOS Stream 9, which shows there are over twice as many instances without EPEL as instances with EPEL.
Keep in mind that the countme data only includes systems connecting directly to Fedora's MirrorManager. Sites that run their own local mirrors are not included. We will never have a complete picture of popularity between these distros. For example, Facebook runs "millions" (a direct quote from their engineers' conference talks, they don't publish exact numbers) of CentOS Stream instances, which is more than everything else in the EPEL countme metrics combined.
https://communityblog.fedoraproject.org/cpe-to-staff-epel-wo...
That said, the "vendor escalate-able only" group is large enough that RHEL is significantly underrepresented in EPEL stats. My guess is that somewhere around 40-60% of RHEL customers use EPEL. For RHEL rebuilds, I would guess that it's probably in the high 90% range, so their numbers in EPEL countme stats are probably fairly accurate. CentOS Stream on the other hand is also underrepresented, as we have countme data for both EPEL 9 and CentOS Stream 9, which shows there are over twice as many instances without EPEL as instances with EPEL.
Keep in mind that the countme data only includes systems connecting directly to Fedora's MirrorManager. Sites that run their own local mirrors are not included. We will never have a complete picture of popularity between these distros. For example, Facebook runs "millions" (a direct quote from their engineers' conference talks, they don't publish exact numbers) of CentOS Stream instances, which is more than everything else in the EPEL countme metrics combined.