I have one 12 TB and two 14 internal hard drives. I also have 6 external drives (two 12 TB, four 14 TB) for 2x redundant backups. All my new stuff and dynamic documents are stored on the 12 TB drive (so that I only have to update the backups for that drive frequently). When it gets fullish I migrate content over to the storage drives and update those backups. I’ve been doing this maybe twice a year.
I also have my dynamic files, photos, docs etc, set to auto backup twice daily to a remote backup.
I only delete content to replace with higher quality.
I haven’t bothered with any sort of raid in nearly two decades. You need proper backups regardless so what’s the point? If I have to run half my Plex library off a USB backup drive for a week while a new drive runs badsector and syncs up… who cares? Merging the drives as a JBOB is nifty and all, but adds complexity across the board without meaningful gain.
Eh, then if your online ID is compromised you’re in trouble. Can’t just burn it and start over.