It's not just US - there is a very interesting article in the British Guardian on this very topic at the moment, how people on £60k-100k are still struggling, even though this was always traditionally a
very decent pay, nothing super fancy but definitely a nice middle class income that would let you pay off your house, have a modest car and go on holidays once a year. Now everything has exploded in price so much that people earning £70k get nearly nothing left at the end of the month after paying their mortgage/rent, bills, childcare, plus some money for fuel to just get to work. I understand that they are all "privileged" in the sense that they can still afford all of those things while many people in this country can't, but the margins are getting thinner and thinner. People can't save up, they can't buy new stuff(which hurts the economy even further), they spend less money on their kids.....it's not great.
Like, me and my wife have a very decent combined income of over 100k, but even then - 10 years ago I would have thought that with that kind of money we'd be living like kings, but in reality it just lets us save some money at the end of the month and not a whole lot else. If we actually wanted to move up from our 900sqf house or get a slightly newer car, it would eat up into all of that quickly. I think we've reached a point now where I literally don't understand who in this country is buying all these new cars and goes on holidays twice a year(forget expensive ones - I mean a few days in Spain with a budget agency). And I definitely don't understand how a teacher on £27k a year(or a nurse) is expected to make ends meet. It feels like an erosion of society from the very core, where unless you are in the top 1% you just aren't even playing the same game.