Start by searching for how to selfhost a photo storage backup. There are multiple ways to do it and the decision depends on your circumstances and preferences, which only you know.
HelloRoot
i moved to sftpGO instead and am quite happy
OP is talking about solutions that include certain features out of the box in an easy to use package.
Rolling out a conglomorate of those features that you've manually set up and ducktaped together by hand is irrelevant. That approach was already possible for many decades.
Dokploy has a web ui with a list of services where you click install and it installs them for you. You can set it up to do the exact same job as OMV but also way less or way more, depending on what you want and need. (by just clicking install on the existing templates, or by entering a custom docker compose if you want to run a nieche service)

So I'd argue dokploy is a perfect substitution (or more like superset) for OMV, but OMV could never substitude dokploy.
free foss alternative, look at OMV
lol no. I used this one for a month and no.
It works but it has the most convoluted GUI possible. No backup system at all iirc. And running arbitrary containers was a nightmare that is not even integrated with the GUI.
I settled on https://dokploy.com/
The closest to your dream is probably https://hexos.com/
It is closed source, but build on top of open source...
They (for now) have a one time purchase license, no subscription.
It has buddy backups. Can run on any normal x86 pc / server (you have to bring your own and install hexos to it). And has a nice and simple GUI for deploying services easily.
I never personally used it. I just have it on my radar. For me, the not so easy but fully free (cost) and open source way works reasonably well. I run my homelab with dokploy.
How did the cat turn out?
FUTO (popularly associated with Immich and Louis Rossman) received some backlash for subverting third-party donor guidelines in the conducting of its grant program
selfh.st should recieve some backlash for subverting the reason for the FUTO backlash in this summary.
The guidelines fuckery is just the decor. The main part of the whole cake is: FUTO platforms a guy that calls himself a fascist and talks racist gibberish.
How is it a map and not a list?
Like, are the containers related somehow?
If you just want to know whats running, there are a ton of docker autoexplore dashboard out there. But I don't think they output a map, just a list.