I wonder if the parent would take that as a challenge to create a startup around creating such an app for the US, since, well, apparently there is no compelling

I wonder if the parent would take that as a challenge to create a startup around creating such an app for the US, since, well, apparently there is no compelling reason absent a pile of data to not think what works in one country won't work in another country .... That's not meant to be aggressive but I think it is a clear indictment of the reasoning used by many others rejecting what I think is a very obvious position.