Podman v5 is likely to be our last opportunity to make breaking changes for several years. As such, we'd like to make as many big changes as possible, and removing support for cgroups v1 certainly qualifies. It substantially reduces our support matrix and will greatly simplify code paths related to cgroups (container and pod creation, mainly). It is still not entirely clear that this is possible; this card will be assigned only after we are confident work can go ahead.