The video is very focused on first order effects. A middle manager automates all their work by writing a few sentences; they produce a "brief" by giving a one sentence input to the AI, doubtless imagining that other humans will carefully read their brief, quietly nodding to themselves and considering every sentence, with passing thoughts about how competent the middle manager is. In truth, the middle manager will soon be replaced by an AI, and the lovely looking briefs produced by the AI will only be consumed by other AIs.
Another part shows the AI creating personalized marketing messages. For a brief time they will work, and then every company will be producing them by the millions, and then customers will stop reading emails at all -- again, the AIs will be writing messages consumed by other AIs.