What does one person's income have to do with anyone else's - why would you aggregate everyone's separate incomes into a single figure in the first place?
And if someone's particular income is insufficient to meet their needs, how do the aggregate population data help rectify that problem?
Of course, you can definitely throw the baby out with the bathwater on that one. If there's completely even income distribution, the only motivation you have to do any work is just because you like to work - and most people don't like to work much. And then people compensate with non-income power imbalance, usually, so things are still not equitable.
I'm not sure I understand the connection though. I don't see how one party having a large amount of wealth, however defined, necessarily precludes any other party from having any amount of wealth.
> whereas if the wealth is more evenly distributed, society tends to make sure everybody's getting along well, with health care and schools and what-not.
But the underlying underlying in statements like this is that wealth originates in the aggregation, and individuals subsequently claim a portion of it, which seems counter-intuitive and false.
Particular people build things like schools and hospitals in particular places, generating wealth for the specific people involved. 'Society' doesn't ensure that people have these goods; people create these goods for themselves, and generate society in the process.
If I make $10/yr I could be the richest man on earth or the poorest. It kind of depends on what everybody else makes too.
If we imagined the way modern technologies might be applied to the productive capacity of a family homestead, for example, the improvement that technology brings to the homesteader's quality of life should be directly apparent, without the need to rely on macro-level metrics at all.