As everyone else has said, make digital copies and treat the originals as backup.

Optical disks do eventually fail. Keeping them in a cool, dark place helps.

Sun (UV) makes the plastic brittle, heat cycling degrades the plastic too.

Also, digital stuff degrades too - storage needs to be on systems that can manage digital degradation.Certain modern Linux file systems (BTFRS, ZFS) have mechanisms to prevent data loss.

Also proper 3-2-1 backup processes prevent data loss.