For me the problems are always when I pull some image (like GitLab) and try to get it to work with podman. Or the hoops you have to jump through with podman-compose (user lingering, systemd services, privileged ports (80,443) [yeah I know it's a feature]). Docker just works, Podman (I feel) still requires stuff that makes it less declarative (to get to a running infra).

Still, having a gitlab runner with a docker in docker setup that can access the host docker socket is not something you do lighty, so I am eyeballing buildah etc.

I guess what really grinds my gears is that I'd use podman a looooot more if it could nicely coexist with Docker. I'd use Docker for the big services and podman for all my own stuff. But that is just not possible (at least not afaik), so it is also difficult to switch step by step (yes VMs, bla bla, but it's all complicating).