You're far more likely to lose data from a hard drive than from a DVD/CD.
A DVD/CD stored correctly away from sunlight and direct heat will usually last at least 10 years, often longer.
A hard drive in regular daily use will eventually fail and crash, possibly leaving the data unrecoverable. 3-5 years is a good lifespan for a hard drive.
If you store all your important data on 1 hard drive without backups, you're sitting on a timebomb.
A DVD/CD stored correctly away from sunlight and direct heat will usually last at least 10 years, often longer.
A hard drive in regular daily use will eventually fail and crash, possibly leaving the data unrecoverable. 3-5 years is a good lifespan for a hard drive.
If you store all your important data on 1 hard drive without backups, you're sitting on a timebomb.