Isn't this a problem?

More specifically: assuming we can't derive it by some clever means, or approximate it from some tax reporting data, isn't it a problem that we can't get such a distribution?

I mean this not as a moral judgement, but more as a system dynamics concern. It's easy enough to see how wealth concentration can destabilize a money/value system absent other factors. So my concern isn't about what's right or wrong socially, but whether there might be a reason to question the implicit trust that the maths will work out.