We will likely never know the exact causes because there is a certain fog that hovers that period of history.

In my opinion, whatever caused that fog (confusion, conflicted or coded accounts, apocalyptic and prophetic writings) *IS* what caused the collapse.

Technology likely plays a role, but as a catalyst to a sociological phenomena. The industrial revolution did something similar (lots of new philosophy with somehow apocalyptic or prophetic undertones, albeit in a different style; war and depression in the following decades; confusion and a fog in history). We're still not over that, and it's only barely visible because we live inside this particular fog, but it's likely to confuse future historians a lot. I see AI as belonging to the same wave.