Is it possible in theory to build a neural network equivalent to the absolutely tiny brain and nervous system any given insect has?

IIRC it’s been tried and they utterly failed. part of the problem is that “the brain” isn’t just the central nervous system – a huge chunk of relevant nerves are spread through the whole body and contribute to the function of the whole body, but they’re deeply specialized and how they actually work is not yet well studied. in humans, a huge percentage of our nerve cells are actually in our gut and another meaningful fraction spread through the rest of the body. basically, sensory input comes extremely preprocessed to the brain and some amount of memory isn’t stored centrally. and that’s all before we even talk about how little we know about how neurons actually work – the last time I was reading about this (a decade or so ago) there was significant debate happening about whether real processing even happened in the neurons or whether it was all in the connective tissue, with the neurons basically acting like batteries. the CS model of a neuron is just woefully lacking any real basis in biology except by a poorly understood analogy.