I was reading this post about the reasons of that: " Many of us have deployed CentOS servers to production environments, trusting Red Hat’s promise that CentOS 8 would be supported through 2029. The Red Hat announcement means that those installs reach end of life after less than 2 years, with the only upgrade path being Centos Stream — AKA being a forced beta tester for RHEL".

https://hackaday.com/2020/12/09/centos-is-dead-long-live-cen...