I've tried Nextcloud and like it quite a bit. I even want to use it again, but I'm not savvy enough yet to understand how backups (and restore) should work on the snap version. That makes me nervous with storing too much there.
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Why don't you use a containerized version? It would be much easier to backup the files.
I'm open to it. I would just need to learn. The snap version seemed easy to use (and it was easy to setup), so I went with that. That's the extent of my experience so far.
Check this from ippocratis: https://ippocratis.github.io/p/install-nextcloud-fpm-docker-container/
There is also available in Greek with some other addons as a comment (use DeepL if you don't understand something): https://linux-user.gr/t/raspberry-nextcloud-caddy2-docker-me-caddy2-reverse-proxy-sto-host/3025
Nextcloud+Caddy2+mysql Dockerized.
I backup user files only. That one is easy since its just a normal folder structure. For full backup you should backup some other folders and database, but Im fine if I lose whatever is written elswhere. Im using docker, but I guess its same for all types.
You can also pay for hosting