Clay tablets were usually used for temporary records, as you could erase it simply by smearing the clay a little bit (a lot easier than writing with on papyrus). The tablets we have exist because of something that causes the clay to be baked into ceramic, which is generally some sort of catastrophic fire that caused the records to accidentally be preserved for much longer.

I can see it happening. Not as a single catastrophic event but, like Rome falling bit by bit, our technological civilization fails and degenerates as climate change (in the worst possible scenario) wreaks havoc on everything.

I know. My first iPad just stopped powering up. WTF!

I should etch something into its glass and bury it in my back yard. Perhaps a shopping list, or a complaint about how my neighbor inexplicably gets into his truck six or eight times a day and just sits there with it running.