[ovirt-users] strength of oVirt compared to others???

Hi everyone! I want to know clear strength of oVirt compared to openstack and kubevirt(VM add-on for k8s). compared OpenStack, I heard oVirt is specialized in long-lasting traditional apps requiring robust and resilient infra while OpenStack is cloud solution. so, backend is suited for oVirt and frontend like web server is suited for OpenStack. but I 'm wondering why these traditional apps are not suited for OpenStack because I think OpenStack encompasses functions(live migration, scale-up, snapshot, ...) oVirt provides. I want to know which features in oVirt make such difference. compared to kubevirt, it seems more difficult to find strength in that both are designed to run legacy apps. under mixed environment, it seems like rather kubevirt has more benefits :'(