Selfhosted

I need some help with some new suggestions for what I want from my tiny homeserver, made up by a Raspberry Pi 4 8GB (passive cooling case) and an external hard drive. That server will not be reachable from outside my home network, if that makes a difference for suggestions.

I am looking for an easy solution that works well on the limited resources of the Rpi. What I mostly need is an app I can self-host that has a nice and well performing gallery function, I got tons of old photos from when I still used digital cameras a lot. Those are already sorted in folders, and I want that app to not mess with that at all, just read them basically.

What I also need is for that app to be able to auto-upload new photos from my phone regularly, so I can include them more easily in backups of my server. I also do not want them to be weirdly hidden in some strange folder structures, so that they remain accessible if I want to change apps again down the road.

Here is what I tried already: Photoprism - loved it in general, but all the indexing was super slow on the Rpi of course. I didn't really need the AI features of it either. It also made quite big thumbnails for the image analysis so it would really add a huge requirement of a ton more storage space just for features I did not want to use, I understand those could be downscaled but the process seemed tedious and resource-intensive. Overall wasn't practical for the Rpi, if I had a stronger server I'd try again.

Nextcloud - thats the current solution I am looking at, since it got all I want. Auto-upload, easy access, no resource-heavy features I don't need. But overall, it is pretty slow on the Rpi for scrolling through photo libraries. I found today the NC Photos app on Google Play Store, which seems to work better than the Nextcloud App to look at galleries, but still seems slow.

Aside from that I found out about Immich, but cannot test it right now since my Rpi runs on 32bit. But it sounded to me like a lighter type of Photoprism app, maybe not fair to say, I know its supposed to be like Google Photos. But the stuff it does for face recognition and what else makes it sound again like a choice I won't enjoy using on the Rpi. Maybe that is an unfair view? I see recently the feature that allows external libraries in it, was added, so that fits my needs.

Anyway, thanks for reading all this, I will end with the question, are there any other solutions that I haven't considered so far?