Its flash memory, physically pushing electrons into a jar and hoping to count them later before all leak out. Endurance tests of SSD drives showed unplugging a worn drive for a couple of days was enough to lose all data. Not to mention SD cards usually get the lowest grade of flash memory.

I never understood why SD cards are so unreliable (or a least have this reputation) as they are usually used in cameras to store pictures. Something that people don't really joke with.

They store things the same way SSDs, do, with electrical charge.

It weakens. That's a shit explanation, I'd definitely look up "how does flash storage degrade".