We'll see if your reading comprehension liabilities extend to self-hosting.

Seafile is extremely easy to set up and does one thing and one thing well.

It does store your data as binaries, so it would be a bit harder to restore than Nextcloud due to that, but I've never had an issue with seafile.

Of course, I didn't have a problem with Nextcloud until an upgrade borked the installation bad enough that even restoring from backup couldn't solve the issue.