I think the point with all of these is that they are “cloud”-based. Except instead of the cloud being someone else’s computer, it’s your own. Let’s take Immich, for example. Sure I could keep all my photos on my phone. But what if I lose or break my phone? What if I have an actual camera with an SD card and I want to offload those photos? Self-hosting lets me keep a backup. I can set up a server with redundant drives that itself backs up to a server in another location with its own separate drives. Thus, I have my own safe cloud storage.
I think the point with all of these is that they are “cloud”-based. Except instead of the cloud being someone else’s computer, it’s your own. Let’s take Immich, for example. Sure I could keep all my photos on my phone. But what if I lose or break my phone? What if I have an actual camera with an SD card and I want to offload those photos? Self-hosting lets me keep a backup. I can set up a server with redundant drives that itself backs up to a server in another location with its own separate drives. Thus, I have my own safe cloud storage.