WHO needs 18-20 TB ANYTHING? The backups take forever, and God help you if you don't have one (or better, two) when it fails. And don't get me started on shingled hard drives.
I have about 10 TB of data, and I would NEVER have it on one drive. As far as my iMac sitting here with its new SSD and my new SSD backup drive and mind boggling backup speeds, I will never go back to hard drives once my new Mac Pro arrives and replaces my pre-trashcan Pro (kudos to Apple for making a top specc'ed one I could finally afford!) I have had a ton of hard drives over the years, and never once got anything approaching data recovery after a crash. Backup, backup, backup.
I'm probably soured on hard drives because my iMac was a uesless brick for two years until I had OWC put an SSD in it. And useless data recovery.