Thanks to image-based distros like Fedora Atomic, I skipped the asking to update step. They download and apply updates in the background, and then the new image gets selected on next boot.
Given Fedora doesn’t do major changes in point releases, nothing breaks (until I do a manual upgrade to a new (half-)yearly major release).
Not having a terminal does not make sense (unless in a business context). For some people (my mum) it’s as if it doesn’t exist anyway, so why remove it.
Podman provides stronger isolation than nixos-containers because the latter only supports rootful containers. Losing access to nixos modules is a disadvantage, altough most services I’d use podman containers for don’t have any modules anyway.
E.g. I’ve used nixos container as a stop gap to use a major beta, because I didn’t manage to adapt the nixos package accordingly.