But, for Docker beginners, there's something to be said for being able to pull a single image and run a container from it, in simple manner. That's a learning tool and a first step, from which an understanding of Docker compose becomes possible.
That is how I began with OMV4 and the Docker plug-in. And I started on Docker because I couldn't get Pi-Hole working, so went for the Docker version, which necessitated macvlan. With the Docker plug-in I managed, with Portainer I still haven't been able to create a macvlan. At present I use the command line to create macvlans and start the containers and I use Portainer only for monitoring (when I suspect something is wrong) and to kill and/or remove a container as that is where a GUI comes in handy. For some reason I never got Docker-compose working and I don't feel the need any more as I keep all my commands for the various containers and macvlans as text files on my laptop, where they are available if I have to reinstall an RPi.
And yes, I still miss that possibility to pull a single image and run a container from it, even though I don't need it any longer. It made it a lot easier to find a nice image doing what you are looking for.