If by popular fantasy you mean replicating the functional profiles of the visual and language cortex of the brain, then yes. These ideas in neuroscience are popular, but not fantasy. I encourage you to read up on functional organization in the brain, it's very fascinating.

> it’s not scientifically useful

Having structured weights in GPTs enables us to localize and control various concepts and study stuff like polysemanticity, superposition, etc. Other scientific directions include sparse inference (already proven to work) and better model editing. Turns out, topographic structure also helps these models better predict neural data, which is yet another direction we're exploring in computational neuroscience.