I am paying about EUR 20 / month for my somewhat paranoid backup system that includes Apple, Dropbox, Synology and Backblaze (and excludes depreciation). Worthwhile all things considering, but if Möbius Sync could sync the iOS Photo Stream ("further down the roadmap") I'd pay EUR 100 or more for that. It would make the backups in my house a lot more manageable.
Does it sync photos from the iOS camera roll? I assume not since the screenshots in App Store don’t look like it. But if it does, and keeps the albums, then it would be useful to me. Currently I transfer my photos from my phone to an external drive using the iMazing app on macOS with the phone connected.
Also worth mentioning if it makes a difference, I only need to be able to transfer photos off of the phone (along with info about which albums they belong to as mentioned), and don't need to sync in the other direction onto the phone.
In the end this might be the most simple and workable solution. Still feels kind of bad having to roundtrip all the data through the cloud when trying to get it from one local device to another.