Its still about memory. Attention span is a measure of memory. Writing stands for the absence of something (a voice or community). Smartphones compensate for so many kinds of absence at once.

Attention is not a measure of memory, on the contrary. Memories are a a measure of attention as if you don't pay attention you will hardly form a memory.

smartphones are not what you say they are, without internet smartphones are close to tracking, privacy invasive, useless bricks. Something like computers with no arms and both knees broken.

Seems like you're mixing very-short-term memory (moment to moment) with very long-term memory. I'm not a neuroscientist, but my experience as a human suggests these are very different capabilities.

You can have good memory and low attention span. Other way round too.