Your ultra-reductionism does not not constitute understanding. "Math happens and that somehow leads to a conversational AI" is true, but it is not useful. You cannot use it to answer questions like "how should I prompt the model to achieve <x>". There are many layers of abstraction within the network - important, predictive abstractions - which you have no concept of. It is as useful as asking a particle physicist why your girlfriend left you, because she is made of atoms.

Incidentally, your description of LLMs also describes all software, ever. It's just math, man! That doesn't make you an expert kernel hacker.