Why does it have to understand how the LLMs are built? They have used gpt-4 to just build a classifier for each neuron's activition, and given the nlp abilities

Why does it have to understand how the LLMs are built? They have used gpt-4 to just build a classifier for each neuron's activition, and given the nlp abilities of gpt-4, the hope is that it can describe the nature of activation of the neurons.