In Jonathan Swift's essay "A Modest Proposal," the impoverished children of Ireland are satirically portrayed as having the advantage of being able to "contribute to the feeding, and partly to the clothing of many thousands" by being sold as a source of food for the wealthy. This is a satirical take on the dire situation of poverty in Ireland during that time. The narrator ironically presents this horrifying suggestion as a solution to poverty and overpopulation.
Therefore, the advantage mentioned in the text is that these impoverished children, according to the narrator's satirical proposal, can serve as a source of income and sustenance for their families and the nation, albeit in a shockingly inhumane and unethical manner.
