I disagree, if anything we need to know what the distribution is before we make such sweeping claims. While pretty much every country has an income tax, which means that we knows fairly well who makes what, there is no equivalent for wealth. Most wealth distributions are estimates which get progressively worse as we near the top percentiles, because really big wealth is very mobile and international.

So yeah before we say: "it always looks like this, it's just about what the parameters are", we need to measure it and have a clearer idea of what it looks like in different societies otherwise we won't be able to decide what the desirable parameters are like.