Technically true but wouldn't going with a cheaper exterior option and using the saved cost for dedicated insulation be more efficient? Aside from airflow it is

Technically true but wouldn't going with a cheaper exterior option and using the saved cost for dedicated insulation be more efficient? Aside from airflow it is usually windows and frames where the insulation property is relevant, otherwise we would see using thicker walls instead of just spraying insulation for cheap development. I mean it is a neat concept but unfortunately efficiency often selects the "boring" option.