Red Hat had open source/community versions of their products, for example OpenShift Origin (now OKD) and RDO (for OpenStack). They wanted to use CentOS but it was not working well because release dates of CentOS were not predictable.

So they acquihired CentOS, but in doing that they changed its target from "community of users [that don't want to pay for RHEL]" to "community of developers that target RHEL". CentOS Stream is much better (though not perfect) for the latter population.

That said, there are many people using CentOS Stream in production (including myself).