What's the question I should be asking, and what data answers it? I'm genuinely asking

Not you particularly, I meant the original: "it feels like every share of income is at its lowest except for the ultra wealthy."

It's ambiguous in several way, no time scale, "ultra wealthy" isn't defined, and "income" somewhat ambiguous.

Median household income is the stat usually used to measure income and it's still increasing.

If my income goes up by 1% and my expenses go up by 2%, has my financial situation improved?