If I teach a real AI about fishing, it should be able to reason about fishing and it shouldn’t need to have read a supplementary knowledge of mankind to do it.
This is a faulty assumption.
In order for you to learn about fishing, you had to learn a shitload about the world. Babies don't come out of the womb able to do such tasks, there is a shitload of prerequisite knowledge in order to fish, it's unfair to expect an ai to do this without prerequisite knowledge.
Furthermore, LLM's have been shown to do many things that aren't in their training data, so the notion that it's a stochastic parrot is also false.