I think the main advantage of volumes is that location is controlled by docker, and these locations aren't as easy to screw up if you mess around with the folder structure.. It also puts all volumes in a common folder (var/lib/docker/volumes) that can be copied to a tar or backup folder using one line, but thats just as easy if you organize bind folders the same way.. Let me know if you find other advatages. 🙂
I have no sunrise/sunset rules, i use light sensors for i.e. outside lighting.. I think about 90% of my "MSR bugs" have been PEBCAC, so check your logic. 😁