This is not true. There is no law of physics guaranteeing some standard income distribution over a society. There at least hypothetically exists societies with

This is not true. There is no law of physics guaranteeing some standard income distribution over a society. There at least hypothetically exists societies with very minimal or no income inequality although in practice this is extremely unlikely. The idea however that the bottom n% of some society have to skew with x deviation from the mean or median is not exactly correct. And the idea that some segment of society will always not be able to afford some amount nominally denominated in that society's currency is explicitly wrong.