So I never dug into this before but I found this interesting chart from the US government [1]
It does seem like a relatively smaller percentage of young people own homes today vs 40 years ago - but not as shocking as you'd imply:
Percentage of people <35 who own a home: 1982: 41% 2021: 38.5%
Percentage of 35-40 who own a home: 1982: 70% 2021: 62%
So while the trend is down - it still seems like over a third of people under 35 own a home, and over 60% of those 35-40 do.
That sounds very far from impossible.
[1] https://www.census.gov/housing/hvs/data/charts/fig07.pdf
Meaning - if guy and girl are married and own a house together, that counts as 2 people towards home owner bucket.
If they are not married, they'd need to each own a house for the same rate to hold.