>> mortgages to purchase properties from elderly owners enjoying hundreds of percent gain after their own mortgage was less than their credit card limit today.
I'm one of those elderly owners as are many of my friends in this community.
The idea that we profited handsomely through house appreciation works, but only if our incomes increased while the value of the house did.
Not necessarily in proportion but at least enough to handle increased real estates taxes - the taxes on my NY house increased almost threefold while I lived there - and maintenance costs.
The other wrinkle is that the aged seller has to live somewhere - and inflation will have raised the cost of the new abode proportionally.
Even with major downsizing on Long Island, I would barely have had enough from the sale of my house to afford a new one.

I chose to move from a high cost area - Long Island - to a low cost area - Central NJ.
Housing costs are much lower and real estates taxes are less than half.

My neighbors, however, are mainly from this area, so they didn't get that benefit.