I disagree with the author's thesis about data scarcity.
There's an infinite amount of data available in the real world. The real world is how all generally intelligent humans have been trained. Currently, LLMs have just been trained on the derived shadows (as in Plato's allegory of the cave). The grounding to base reality seems like an important missing piece. The other data type missing is the feedback: more than passively training/consuming text (and images/video), being able to push on the chair and have it push back.
Once the AI can more directly and recursively train on the real world, my guess is we'll see Sutton's bitter lesson proven out once again.