Using rhscl container images in Fedora and CentOS

I noticed Fedora and CentOS have relatively few containers in their registries (registry.fedoraproject.org and registry.centos.org respectively). On the other hand, it seems that Red Hat Catalog allows Fedora users download and use rhel images freely even without a Red Hat subscription. Is this OK? Docker images are also available and seem to be the Podman’s default registry to look for containers, but I suspect maybe images from the Red Hat family would be more compatible on Fedora and CentOS. Would someone please clarify about this a bit?