Can I ask what doesn't work with Nextcloud to your expectations? Just sounded like "works alright" implies something is off from what you'd like. I am asking because I have recently set this up for myself and haven't noticed any issues yet. Well apart from a recent issue with one of the latest app updates crashing those auto uploads.
The sync on Android itself is pretty stable. Every now and then it throws errors about not being able to sync but those could be because of bad reception.
The Nextcloud app on Android has another weird error for me. It doesn't show the content of a notification (like "Update for app xyz available") but "NEXTCLOUD_NOTIFICATION". I tried to resolve it using different approaches from the internet but it followed me even to a new phone. I just gave up for the time being.
The sync with iOS is somewhat bad. To get all the images from my wife's phone to the cloud I have to plug it in, deactivate screen timeout, and open the app. Sync will stop once I close the app.
Last but not least compared to iCloud/Google Photos watching and browsing the photos on a device is just way slower. I understand why that is but in the end it's just an annoyance making the switch harder for people in my family. They understand why I am passionate about selfhosting and privacy but they still have a reasonable expectation that things just work.
All in all nothing really severe. Little annoyances along the way. I am still quite happy with the solution all in all.
Thanka for elaborating so detailed! I can mirror your concerns, seeing mostly the same issues like slow browsing of images. But overall I am ok with this too.
They understand why I am passionate about selfhosting and privacy but they still have a reasonable expectation that things just work.
That's somewhat where my head is at too at the moment. I do want to go the privacy route but I do also want something where it can "just work" (hence why I'm looking closely at third party solutions like entee and filen or proton drive).
I do care about privacy, but having all the creature comforts that companies like Google has provided is still a bit difficult to let go.
Sync will stop once I close the app.
This is an iOS limitation, so no going around that unfortunately.