For a two-income family with two preschool aged children, the article is not that far off. Some items might be a bit over, but others might be a bit under. overall, I would say it is about right. The numbers will change once the children are old enough to go to school. Obviously the numbers will be very different for people who are single, married without kids, or even those married with one full time parent.
We at one point were raising two toddlers in NYC, while making substantially more than $350k combined. We did not feel poor, but never felt comfortable splurging on anything. We lived in a two bedroom apartment (and converted the dining room into a bedroom after DD was born), and we did not own a car.
It is definitely worth pointing out, that the table in the article is based purely on cash flow, not savings or wealth accumulation. A substantial part of mortgage payment is principal pay down, essentially building up house equity. Also, the 401k and 529 are both $’s going straight into investment account. Between these items (and whatever I have missed), there is indeed some buildup of savings.