I use Seafile (https://www.seafile.com/en/home/) (hosted on an RPi on my home network).

Then I back up the actual Seafile data files on the server with Borg (https://borgbackup.readthedocs.io/en/stable/), which has the wonderful option to encrypt the backup. The Borg backup is on the same server/drive. Then I sync the entire (encrypted) borg backup to S3 every night.

This offers self-hosted file-syncing (ala Dropbox) w/ an encrypted offsite backup (make sure you keep a copy of your key in a safe place though). Honestly, was a pain to set up, but haven't had a problem with it yet, and my test restores work great.

I only pay for S3 storage.