Here is a simple video that breaks down how neurons work in machine learning. It can give you an idea about how this works and why it would be so difficult for a human to reverse engineer. https://youtu.be/aircAruvnKk?si=RpX2ZVYeW6HV7dHv

They provide a simple example with a few thousand neurons, and even then, we can't easily tell what the network is doing, because the neurons do not produce any traditional computer code with logic that can be followed. They are just a collection of weights and biases (a bunch of numbers) which transform the input in a some way that the computer decided that it can arrive at the solution. GPT4 contains well over a trillion neurons, for comparison.