Doesn't that rely on the assumption that gains are uniformly easy to generate across the income spectrum? As a thought experiment, imagine you had a million do

Doesn't that rely on the assumption that gains are uniformly easy to generate across the income spectrum? As a thought experiment, imagine you had a million dollars and wanted to use it to make more money. Then imagine you have a thousand. Isn't it much easier to make money, when you already have money? Things like diversification, favored rates on investment and economies of scale/scope only appear at the upper end of investment. While we may be able to tweak things, the fact remains that gains may just be easier to come by at the upper end of the spectrum.