Just an idea: perhaps all of the end devices should have at least some high reliability storage. This would enable local applications that require high data durability and integrity.

Probably it'd require ECC RAM to prevent in memory bitrot, multiple copies of blocks (or even multiple physical block devices) with strong checksums.

Perhaps this data should somehow "automagically" sync between all locally available devices, again protected with strong checksums at every step.

(This idea requires some refining.)