What's happening is that upper-middle class families really do run out of money after saving for college, sending the kids to private school, both driving two new cars, and so on. They think of those things as basics and forget that those basics are unattainable to most.
Right. Hedonistic treadmill/keeping up with the jonses/we rate our lives compared to our peers not compared to objective rock bottom etc... And of course "fucking baffling" was a bit of a rhetorical flourish. Certainly we all understand how they've managed to spend all their money. It's the "and yet they keep spending all their money" that makes us want to grab them by the shirt collars and cartoonishly backhand them.