I agree to a point. I’ve been buying used SAS drives for cheap on eBay. Not a single failure in the dozen or so that I’m running right now in my server. I have a few spares sitting on the shelf just in case but I’m not expecting to use them for some time.
Unraid checking in. 150TB ish. Dual parity for media files on XFS drives. Can lose 2 drives before array data is at risk, and even then if a drive fails, I’d only lose the data on that drive not the entire array.
Important data is on ab encrypted ZFS array which is snapshotted and replicated hourly to a separate backup server and replicated one more time weekly to 3.5” archive drives which are swapped out to a safe deposit box every few months.
I used to use rsync to do it but snapshot replication with sanoid/syncoid does the same thing in a tiny fraction of the time by just sending snapshot deltas rather than having to compare each file.