I believe it is necessary for FreeBSD to get OCI and Dockerfile compatibility to stay in the game and attract curious users.
BUT I personally started using Jails because I really got tired of the "Docker" workflow and ergonomics.
After 25 years Jails are almost perfectly integrated in the OS. You will find an '-j' option in most command and of course ZFS make everything better. It is actually so good that you might not even need a management tool like Bastille or iocage in many cases...
Syntax like Dockerfiles means a lot. Does it manage compositions and the intermediate states towards the final outcome and is there Docker2Kleene conversion tooling?
I hope OCI images for FreeBSD really take off. There too many tools which do jail management.