Right now, I have around 20TB of data in redundant ZFS mirrors, so I am somewhat protected against any single drive failing. Critical data is backed up at various cloud providers, but that's only a few gigs of all my data.
Looking at S3 pricing, It seems rather unfeasible to back up my data there or on the other "big" cloud providers, as it would cost me around $180 with AWS or half of that with backblaze.
You could look into AWS Glacier or S3 Deep Storage tier. If you have 20TB stored that’s about $20/month(YMMV) which isn’t wonderful but that’s a lot of data so it’s understandable.
Being a cheapskate, if I can get something back or it’s not crucial it’s on a RAID array with snapshots, everything else is either encrypted Duplicati backups to Google Drive (Windows) or encrypted borg backups to Borgbase(Linux)
Borgbase is very reasonably priced and if you have a large storage space in GDrive due to having one of their other services it’s a good use of it.
Running 2 redundant unRAID systems which mirror ZFS snapshots between systems. The main system(150TB) is the one that has all of the SMB connections to the rest of the network and allows modifications to the filesystem (with a valid login). The backup system has no public shares and exists only to replicate the main system and is just large enough to store personal documents and such.
For critical data (read: personal documents, family photos, etc), in addition to the backup server, I also keep an 8TB drive in a safe deposit box, and I bring it home about every 6 months to rsync all of the latest updates to it from the backup server.
For media (TV shows, Movies, music), it's only "protected" against failure with unRAID's array system with dual parity. I don't bother with backups at all, because it's very large, and all easily replaceable.