I have magnetic media that is still lasting over 20 years of age. When you don't use it, its life extends a lot. of course if you are going to use teh hard drive every d ay, it will be prone to crashing.
My CDs started to deteriorate after 6 years. The DVDs, likewise. I lost data due to slight CD errors. Ok, it was, let's say, 10% of the backup total, but it is still data loss.
Passing stuff from flakey optical media to less flakey optical media sounds silly to me when I can have ONE hard drive with everything, tucked away safely which will last a LOT longer than optical media and, with today's costs, it's really affordable.
My A600's 30MB HD is still alive after 20 years. I assume it is because I have stoped using it like 10 years ago.