Software wise I find stuff pretty easy to set and forget. It's hardware that's always been the issue for me. When your power or internet goes out, everything goes down. While you move property, every thing is down. Currently my server has developed an issue with randomly crashing and rebooting I haven't been able to resolve yet.
Using a VPS entirely removes the hardware aspect, but it also mostly defeats the point of self hosting.
Your personal photos likely do not need 99.99999999999% of availability, especially if you still have a local copy of the most recent and interesting ones on your smartphone.
I don’t think it defeats the point at all. Uploading photos to Google is a massive privacy concern. Apple is maybe better in that way, but very limited cross-platform support, and when I’ve tried it, poor performance & pricing. Neither do well at higher end photography either.
I self host for privacy, which makes me feel uncomfortable about all my private data sitting unencrypted on a server I don't control. It's better in that you don't have fully automated google AI scanning your data, but it's still exposed. None of the self hosted apps are designed with e2e encryption in mind so you'd be better off using icloud.
Lets say you don't leave it unencrypted on disk, only in memory. Do you really think vps providers are slurping your personal data out of a VM's memory in the same way google do dragnet personal data gathering? If your adversary is the government, sure they probably can do that, but otherwise it seems unlikely.
Cost wise on the right hardware it is very cheap to run, add the privacy/personal control aspect it's no wonder so many people do it.