Inflation says that you would rather prefer to live it today's society at say $60,000/year (with smart phones, cars, Internet TV), than yesterday's society at say $50,000/year (with two maids, but none of the technology). Introspecting, I would say the above decision is true for me.
An alternate perspective (not contrary, just different)…
My uncle and late aunt were linguists in Central and South America. They were funded modestly with American funds.
When abroad, they did not have a car, but they did have a housekeeper (cooking and cleaning) and one or two nannies (two when their 3rd kid was young). They got around by scooter, or taxis if necessary.
When they came to the US to raise funds, my aunt always complained about how hard it was to manage everything even though they were frequently given loaner cars and a lot of free food. Apparently the extra labor around the house made a huge difference for household management, and apparently that house help was worth way more than a car for them.
When I lived abroad in a lower CoL country, I rarely cooked just because I could eat out very cheaply and relatively healthily.
If Christie enjoyed an 'upper-middle-class' lifestyle on an official inflation-adjusted $50k salary, then it's clear that the offical inflation figures do not actually measure the 'cost of living', but something much more diffuse and subjective like the 'quality of living'.
If the cost of living hadn't "increased", then the middle class would still be tiny, and we wouldn't be in it. The whole thing would be moot.