Because Rocky does every trick they can to get Red Hat source RPMs (they're the reason Red Hat put the srpms behind a paywall in the first place). CIQ then undercuts, and sells support for Rocky because they don't do any engineering and don't contribute anything upstream. Alma on the other hand bases on CentOS Stream (which is ABI compatible with RHEL) and maintains its own SIGs and contributes back to the project upstream. Rocky is a leech, but Alma actively makes entire ecosystem better.