Both on occasion.

Export can get
everything with a single action (but it does take some time) as it will back up toy CONFIGURATION and all KNOWN Libraries.
So that is what gets done if I make a major change (add/remove Libraries)
For 'daily' or Incremental backups, I use Freefilesync to another PC.
It takes under 3 minutes typically to MIRROR designated folders (Libraries, configuration) changes (adds, deletes, updates)