In an interview Sony gave to AV Watch recently, the company admitted it's going to "gradually end development and production" of recordable Blu-rays and other optical disc...
Don't fret, Verbatim will still be making recordable BD-Rs. However, this will mean that there will be no more 128GB BD-Rs, we'll be stuck with only 100GB BD-Rs (Sony is the only company that makes 128GB Blu-rays).
I recently ordered a pack of 128GBs from Japan. I'd recommend you do the same, because the prices are gonna skyrocket.
Backing up personal data, mostly stuff from my childhood that is irreplacable. Sure, I could just put them on a HDD, but then I'd have to replace it every 5-10 years. Data stored on Blu-ray can last a long time.
Rated for, but that doesn't mean they're all actually manufactured to that standard.
CDs were rated for like 50+ years originally I think. We found out real quick that was an optimistic number, especially when you buy the cheapest thing around.
ISO certification does require a bit more effort than just the bare minimum necessary to legally advertise specific claims about a product.
That doesn't mean all M-Disc manufacturing is immune to shitty business practices of a manufacturer, but they do have to meet certain manufacturing specifications.
The international organization for standardization has rated them for archival use in the hundreds of years. This is not a maybe and the Wikipedia page/link I shared above goes over the testing methodology
Assuming the drive spins back up after being left in a cupboard for 15 years, if you're still even able to find a computer compatible with whatever cables it used back then. But yeah.
If proper SATA ever goes away, I'd wager that there will still be SATA-to-USB adapters on sale. Heck, people still find ways to connect floppy drives to their modern PCs.