Now, not so much. Do they even know who uses Alm or Rocky or Amazon Linux or Oracle Linux? Do these companies share their CRM data with IBM/Red Hat. Probably not. And of course both are in the business of providing support and consultancy themselves. IBM does the hard work and those companies reap the benefits. Very noble but not very smart.
The whole setup is weird. The only reason for these distributions to exist at all is that IBM/Red Hat refuses to distribute their own software directly. They are still doing the work and providing it for free in source code form (not optional) which is why this works at all. But they've created this whole side hustle that is cutting them off from their own user base. How is that in any way a smart business strategy? All they'd have to do to fix it is roll back to just providing Red Hat to people that want it for free and then up-sell them on support contracts. That's business they aren't currently getting.
https://www.suse.com/c/suse-liberty-linux/
Oracle Linux 9 also dropped a week ago, and their support is available if increasingly expensive.
The problem with both of these is app support certifications. Microsoft SQL Server (for example) is solely supported on RHEL, although it's obvious that they build on CentOS.