Mortgages are necessary unless you want to continue to rent. Single story two bedroom houses are selling for $250,000, while the people paying for them make $60,000 a year. People can't buy those outright. Meanwhile to rent the same thing is $1,400 a month and you don't get to sell part or whole of the rental property to recoup some of the cost you spent over the years. One year of renting comes out to $16,000 which is almost the equivalent of the average 8% down payment on that $250,00 mortage.
And private schools aren't the killer. Daycare is. Daycare's gotten stupidly expensive, and with so many families where both parents are working it's necessary in order to take care of children younger then nine or so who can't be by themselves at home. Most people don't live near family that can take care of those kids these days, so it's either professional childcare or nothing.
As for expensive hobbies? Dude everything's fucking expensive now. Gaming's gone from $129 for a PlayStation 2 and $40 for a game ($234 and $72 in 2026 money) to $649 for a PlayStation 5, $70 for a game, $30 for the three additional packs that were split from the base game to drive up profits, and $10 every month for PlayStation Network access. Want to go collecting vintage sports jackets? Good luck outwitting the scalpers buying them all in secondhand stores for $15 and then selling them on Etsy for $120. Want to get into crocheting? Either brave the yarn from sketchy Chinese online shops that likely won't even hold up to a single hook or pay $20 for a roll of it at Michael's or Hobby Lobby because every other crafts store was murdered by private equity. Collecting Pokemon or Magic The Gathering cards? You're lucky if the store display box isn't empty from scalpers filching them all to resell the meta cards online for 20% more. Learning an instrument? With the recent closings of so many luthiers and the wood import shortage from tariffs buying even the shittiest guitar is like $175 now, where as six years ago you could get one for $100.
That's not even getting into how many more bills and monthly subscriptions there are now compared to twenty five years ago that suck people's money away.