If there's private school and one or two teenage drivers, $80,000 doesn't get as far as you think. Your point is well taken and valid, but cost of living is a real thing.
It doesn't even require private school to stretch $80K - it's all very locality dependent and the biggest driving costs are housing, healthcare, and transportation. And if childcare is in the mix, it's a budget buster.
For example, a family with $80K in income in Lawton, Oklahoma would need to make almost $118K in Atlanta to have the same exact budget arrangements. That's a huge difference.