JK: It doesn't necessarily have to be a defect of the card itself - i.e. could just as well be that just the file system has been corrupted for whatever reason (for example, I once had a HDD in my notebook that became corrupted by a few defective memory cells in one of the SO-DIMMs...). So, if you're curious, you could always try a few things - like for example, depending on the format, perform a file system and file check (e.g. via chkdsk) for more thorough failure diagnosis, or/and reformat and refill the card and see, whether it works again...
jb: Whether flash cards outlast HDDs still has to turn out, I'd say. In my experience even very old HDDs (the oldest ones of mine I still have date back to the early 90s) often still work no problemo. Checking some of these can really become rather cumbersome in the meantime, though, especially because I haven't got some form of SCSI controller for any of my newer computers anymore - so for checking the old SCSI HDDs I also have to reanimate one of my old computers, which often is a lot more problematic now...
Greetings from Munich!
Manfred / lini