The thrust of the article [1] is that the income defined as "Poverty Level" (60% of disposable income), is higher in the US than in many European countries. This definition is based on disposable income, which does not account for spending on childcare, healthcare, housing, etc., many of which are heavily subsidized, or simply less expensive in these European countries that are being compared to the United States.

[1] https://mises.org/wire/poor-us-are-richer-middle-class-much-...

Note: I appreciate your calm responses and engagement of the arguments. I concede that I should have included some refutation or concession based on the merits of the article themselves in my original reply.

Edit: to add another source refuting the Mises thesis, stating that income inequality is highest in the US among G-7 countries (https://www.pewresearch.org/social-trends/2020/01/09/trends-...)