Using rhscl container images in Fedora and CentOS

I noticed Fedora and CentOS have relatively few containers in their registries ( and 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?