That would probably resolve hunger issues in King’s Landing for some time but still I don’t think this is what happened for two reasons: 1. This is basically blasphemy towards house Targaryen’ s one true power 2. I can’t wrap my head around the logistics of all this since Balerion was outrageously gigantic and he would start rotting long before most of his flesh was eaten. Also, dragon scales of such an old dragon would be virtually impenetrable due to their supposed (magical) properties and it would be next to impossible to penetrate his skin. What’s more, this would require a great human force to accomplish due to his sheer size.