Nextcloud, despite you’re not considering it. You can disable or not install the apps you don’t need, like Calendar, Contacts, Photos, Dashboard, Activity, etc.
There’s also a fork of Filebrowser, called Filebrowser Quantum, which I’ve been interested in, though haven’t tried yet: https://github.com/gtsteffaniak/filebrowser
No, I haven’t tried OC. Lot of people still prefer it over NC. I think both have come quite a long way since then.
I wouldn’t say Nextcloud is hard to maintain, even less so if you keep the number of apps to a minimum. The initial setup may require some work, but small instances are mostly plug and play.
Note that I’ve never used AIO. If going for containers, the community images are better, despite AIO advertised as the official method. I recommend using Podman, check out
https://github.com/0ranki/nextcloud-previews
Also a blog post: https://oranki.net/posts/2025-01-02-self-hosting-my-way5-nextcloud/