I would have hoped they would attribute LLM success to the structure of language itself. As the authors say, even small linear models can approximate CoT and solve complex tasks. So it's not the model. It's the data.
Analogously, humans have very different brains when looking at low level, but brains still learn the same language and skills about as good as any other brain. It's not the brain or neural net (the models) but the data that shapes them to become smart.
This insight has consequences on how we view training data and where to focus our work to improve AI and human brains - improve language, ideas & chains of thought. This resonates with recent discoveries in fine-tuning and training small models like phi-1 and phi-1.5 who were trained on "textbook quality" data of high diversity.