www.makemkv.com

Not unexpected, but as I go though my library of physical media, I'm discovering that many of the CDs and DVDs I burned back in the day (~20 years ago in some cases) have become unreadable. Fortunately, I have digital copies of most of these already, so it's not a catastrophe. I do recall warnings about the limited life of burnable media. There was only one vendor (Kodak, I think) that offered "archival" discs. These were significantly more expensive. I wonder how those are doing?

That's normal, chemical processes destroys the disc over the years. From my experience, the lifetime is 10-15 years.

An original DVD / Blu-ray is pressed from an master and not written by laser in an disc writer, so it's totaly different.