My wife and I graduated undergrad with no debt. I didn't pay for my last two years' tuition; my wife had a full ride. State school, but still.
My wife lived with her parents for eighteen months, saved up, and put down a downpayment on this house. She was 22 and that downpayment was like $10k. She paid $1200 a month for the mortgage. I was far too happy to pay $650 a month for 1400 sqft with a view of the lake; any rent-vs-own calculator back then would say "keep enjoying your view." Of course, that apartment is now six half-million-dollar condos.
I got a different read from the article than you did - what I read was basically that "adulting" has become such a thing because the standard markers of adulthood have been pushed so far out by financial circumstance that really, there's nothing you can't do without your parents' help anymore.