You do the same to hard drives, you re-record the data periodically you have to do the same with DVD. Neither media can be left on a desk drawer for 10 years and expected to work.
When you re-record data with a hard drive, is it the hard drive that is degrading, so you need a new hard drive, or is the information stored on it just degrading, so you can use the same hard drive, but just delete what's on it, and re-copy the files onto it?