I have rsync cron jobs that backup to an Olimex NAS [1]. Their mainline support is great and the box has been running find for a few years already. The only problem is, it only supports 2.5" HDDs, so you are limited to 4TB. Power consumption is less than that of my dish washer on standby.

From then on, I backup to Google Archive Cloud Storage over restic [2]

[1] https://olimex.wordpress.com/2020/03/13/bay-hdd-sdd-is-easy-...

[2] https://cloud.google.com/storage/docs/storage-classes