You about said it. Average Joe uses his ODD only for installing OS, certain software and games.
But as for the backups and other offline storage go, ODD is still a very viable and about the only method for the Average Joe.
If Joe needs to backup his documents and pictures, then I'd say a few USB sticks are the way to go (let's say under 100 gigs). But how about if Joe is an avid photographer, records a lot of videos with his 1080p camcorder and records a lot of TV too. We are talking about several terabytes here. Let's say 5 TB.
Cheapest SSD prices around here are now 70â‚¬ / 120GB -> about 3000â‚¬
USB sticks are a bit cheaper at 30â‚¬/64GB -> about 2400â‚¬
Mechanical HDD is NOT a place for backup (internal or external) but the price is around 90â‚¬/3TB -> little over 150â‚¬ with no RAID.
Not great, but OK BD-R discs are 55-60c a pop. Each disc holds 23,2GB, so we need at least 221 discs -> little over 130â‚¬
Of course LTO-5 tapes are about 30â‚¬ here with 1,5TB uncompressed capacity, so backupping 5TB would require only 100â‚¬ worth of tapes.
...though the tape drive here costs as much as Average Joe's house, so not a viable option and ODD's are more practical than tapes.
If someone has a better option than backupping to ODD, I'm all ears...