Rocky is "winning" if by "winning" you mean more widely used. Here are some graphs charting usage through EPEL statistics: https://rocky-stats.tiuxo.com.
The source used to generate the graphs is available at https://github.com/brianclemens/rocky-stats, however please be kind to the Fedora servers and don't download the stats database too often if you use it.
Also Rocky Linux is far larger in terms of community size, etc.
As someone who has had to use Oracle Linux for quite a few projects due to requirements, those graphs are actually a sobering look on things.
Of course, all of those distros are reasonably similar at the end of the day, but it's pretty clear that the popularity of Rocky Linux, Alma Linux, and even CentOS Stream are all formidable.
Also note that genuine RHEL users generally don't want to use EPEL that is out of support.
> The EPEL repository is used by a significant portion of Enterprise Linux users. The data they share are unbiased, and it is reasonable to assume approximately equal proportions of users of each Enterprise Linux distribution use the EPEL repository.
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.
The source used to generate the graphs is available at https://github.com/brianclemens/rocky-stats, however please be kind to the Fedora servers and don't download the stats database too often if you use it.
Also Rocky Linux is far larger in terms of community size, etc.