Right, so jails do not have images or any of the tooling around building and distributing images which is the vast majority of what makes up docker. This is why

Right, so jails do not have images or any of the tooling around building and distributing images which is the vast majority of what makes up docker. This is why cgroups+namespaces are much closer to jails than docker is. There are systems which build upon jails such as iocage and ezjail which are more similar to docker.