Comment by carlwgeorge

It's not a totally different distro, it's a different variant of the same distro. Back when I was on the release team I would create builds, release them in CentOS Stream 8, then a few months later release them in CentOS Linux 8. It was the same content on a different schedule, released once it passed QA rather than batching up most updates into minor versions.

CentOS Stream has major versions and EOL dates, and thus is not a rolling release. It functions as the RHEL major version branch and follows the RHEL compatibility rules, so it's the same major version stability as RHEL.

While you may have considered bug-for-bug compatibility the main feature, it was a major point of frustration for many users and the maintainers. That model means you can't fix any bugs or accept contributions from the community. CentOS finally fixed both problems by moving to the Stream model.