SD cards are not intended for long-term archival purposes, not 10+ years. They don't go bad per se, but the data on them may not be readable after slowly discharging offline in cold storage for a decade or more.
How about bluray? 25GB for ~$0.70.
Personally had so many sd cards, and even usb sticks fail that adding another type of storage as a backup for important files really makes a lot of sense.
That would be 170 CD’s - nearly 30 DVD’s - which will eventually suffer disc rot.
DVD/CD write speeds are very slow, comparatively speaking to even USB 2.0 transfer speeds - and increasing the speed, in my experience, makes exact copies of discs extremely error-prone.
Explain how this is efficient? Genuinely curious, with the price of solid state storage these days.
(I understand even solid state storage has a shelf life, but at least it also can’t be so easily harmed as a CD/DVD)