1) Someone runs into an interesting problem that can potentially be solved with ML/AI. They try to solve it for themselves.
2) "Hey! The model is kind of working. It's useful enough that I bet other people would pay for it."
3) They launch a paid API, SaaS startup, etc. and get a few paying customers.
4) Turns out their ML/AI method doesn't generalize so well. Reputation is everything at this level, so they hire some human workers to catch and fix the edge cases that end up badly. They tell themselves that they can also use it to train and improve the model.
5) Uh-oh, the model is underperforming, and the human worker pipeline is now some significant part of the full workflow.
6) Then someone writes an article about them using cheap human labor.