The main reason is that (post-acquisition) Redhat, in a push for monetization, killed Centos, thus forcing lots of people to quickly find a replacement… and Op

The main reason is that (post-acquisition) Redhat, in a push for monetization, killed Centos, thus forcing lots of people to quickly find a replacement… and OpenSUSE happens to be the biggest close enough relative (rpm-based etc) distribution suitable as a replacement. Not that there wouldn't have been even closer candidates (e.g. Alma Linux or Rocky Linux), but those are much smaller (community, backing, etc) than OpenSUSE. That on the server side… and well, on the desktop side there's the fact that some people dislike the new breed of sandboxed package formats (with fedora pushing flatpak and ubuntu pushing snap), often without seeing the differences between snap and flatpak. Personally, I think that sandboxed isolation with cgroups/namespaces and bind mounts etc is a step in the right direction, but snap is a total disaster while flatpak does make lots of things right, Redhat/Fedora did made a huge mistake in going for a split-up server/desktop segmentation with RHEL covering the server side with OCI container based solutions (OpenShift and such) and Fedora covering the desktop with Flatpak that is too restrictively desktop-oriented. RPM lacks the isolation/sandboxing of Flatpak and OCI containers, but it was a unified format, and I don't see any good reason that the successor of RPM wouldn't be.