story
But having a strong textile manufacturing industry promotes the development of other adjacent industries (e.g. dyes, chemicals) that would not be able to stand on their own initially, and can output products that are useful to more than just textile manufacturing. It easier to develop a new industry if the country already has other industries that can support its growth.
In a sense, it is like a tax on clothes, paid by the consumers, funding textile-adjacent industries, but directed by private actors rather than the government. If it pays off, other things become cheaper and potentially offset the increased cost of clothes.