That said, you criticized log(consumption) above because it doesn't measure "social structures" and "inequality". Those things are pretty explicitly not how the economy is serving the population.
Income is easily measured for individuals, and aggregate consumption is easily measured by merchants. This is why we have a progressive income tax and not progressive consumption taxes. It could be done, it is just more difficult.
You can repeat as often as you wish that "inequality" is not relevant, but you are wrong. Utility is increased more if $1 is earned/spent by a poor person than a rich person, ipso facto inequality is bad for utility, all else being equal. My reference to the economy serving the population, is just a reference to utility, as opposed to any other linear measure such as GDP.
But you wanted to measure 'average "utility"', not "social structures". Utility comes from consumption, not income. You are right that tracking consumption would fail to be a proxy for income inequality (as you now seem to want it to be) because consumption inequality is vastly lower than income inequality.
At this point, your metric sounds less like an improvement on GDP, and more like just some other random thing you want to track.