The Japanese take out mortgages for two, three generations. We are on our way to 100 year mortgages, that is we just share crop the land and shack we are on.
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That will mean that interest rates must stay low. Once the rate reaches a high enough point the payment on a twenty year mortgage would be almost the same as on a one hundred year mortgage. If you can’t afford the long term you can’t afford the short term either if the rate is very high.
I think what happen in Japan is that in order to keep the Bank books nice and tidy, they did everything to keep home prices up, but wages in real terms collapsed. So in order not to have the home market collapse, the banks wrote multiple generation home mortgages, pushing the payments out fifty, sixty years, just like we were/are pushing car payments out five or more years.
Anyways, young people in Japan are not having children, the population is collapsing and eventually the banks/gov ( One and the same) will have to, or not, deal with the reality of few taxpayers and much debt.
But, we are not Japanese.