I'm not sure that's true. I would love it if so!

https://www.canada.ca/en/conservation-institute/services/con...

Just one article discussing it. Do you have a source to back this up? M-DISCs are getting hard to purchase these days, and I have a lot of stuff I want to put on them which I likely will want to look at in 30 years.

Mdisc uses a special very hardened layer thats set it apart from other discs. That is why long term storage works so well.

"Instead, the M-DISC™’s data layer is composed of rock-like materials known to last for centuries. The M-DISC READY™ Drive etches the M-DISC™’s rock-like layer creating a permanent physical data record that is immune to data rot. The stability and longevity of the M-Disc DVD has been proven in rigorous tests conducted according to the ISO/IEC 10995 test standard for determining data lifetime of optical media."

https://www.mdisc.com/faq.html

Are you suggesting blueray will last as long as M-disc?