Most financial reporting seems to be building simplistic narratives around highly complex dynamics and the largely arbitrary reactions of the masses to those dynamics.

My simplistic narrative, based mostly on the timing of market I observed, agrees with yours: the tech selloff was sparked by Google's earnings report. Mostly the fact that Google's Search cash cow seems to be getting cannibalized by its less profitable AI overviews, compounded by their cash flow turning negative due to their insane CapEx bill, which is only going to keep going up. And then Amazon reported a similar plight.

Hilariously, this even affected MSFT, which actually had a good quarter while being the only hyperscaler with positive cash flow, initially sending the stock to record highs. And then Google's earnings report hits and drags everything down. Satya must have been pretty annoyed.