I'd argue that our ability to recall individual moments has gone down, but the sum of what we functionally know has gone up massively.
With AI trained on increasingly generic input used by the casual, then the quality of our production will increase in quantity but decrease in quality.
I am not arguing to abandon the written word or LLMs.
But the disadvantages--which will be overlooked by the young and those happy to have a time-saving tool, namely the majority--will do harm, harm most will overlook favouring the output and ignoring the atrophying user.
I'm sure somebody out there would argue that the answer is yes, but personally I have my doubts.
Plato’s (or rather the Egyptian king’s - IIRC) fears were not unfounded, since a lot of people do not operate this way (sadly I see this with some peers), however overall the effect could still be positive.
Writing distributes knowledge to a lot of people, without it you have to rely on a kind of personal relationship to learn from someone more knowledgeable (which can be better for the individual mentee though). So maybe it increases chances of learning (breadth of audience) at the cost of the depth of understanding?
But sometimes the new tech is a hot x-ray foot measuring machine.