I think you&#x27;re right about these points, except they miss the surprising aspect of the theory.<p>Imagine there were two countries in the world, say France and England, and France was better at making every kind of product. Most people would conclude that England would need to protect itself from France by limiting trade. Comparative advantage tells this is not true - England will always be richer if it trades, no mater how good France is at manufacturing. That is the key insight.<p>Yes - England could train its weavers, or entice weavers from France, or develop wine growing regions, or focus on services. But no matter what it does, it will always benefit from trade. Comparative advantage isn&#x27;t telling you about training, labour mobility, or the difference between goods and services. It&#x27;s telling you about trade in general.<p>Of course it&#x27;s a model, but many economists find it compelling.