Samsung Evo Plus 970

I'm new to these m.2 drives. I'd heard talk about SSDs years before they came out and understood they would mean 100% reliability and decades of service because there are no moving parts. I've seen talk of drive failures and seen how well rated these Samsung drives are.

Can someone please explain how it is possible for these drives to fail?

Nothing is 100% reliable. However, Samsung SSD's are among some of the best, if not THE best, SSD's on the market right now for speed and reliability. Failure could mean a NAND chip has bit the dust, just because there's nothing moving doesn't mean there isn't anything on the drive that can't break.