Nextcloud asked in a poll at https://mastodon.social/@nextcloud@mastodon.xyz/115095096413238457 what database its users are running. Interestingly one fifth replied they don't know. Should people know better where their data is stored, or is it a good thing everything is running so smoothly people don't need to know what their software stack is built upon?
If you're using the AIO image, backup/restore can handled for you, so no need to worry about the manual steps involved. Or if you're using a VM, a backup can take the form of full system snapshots, so also no need to understand how data are stored. Granted it's always helpful to know what your running, but not necessarily requisite, even for backups.