The lack of equity building for such a long time in a 50 year mortgage would seem to make the potential for being "underwater" (owing more than your home is worth) ... highly likely.

A lot of the fixes for that in the pros is "well people will refinance and make good decisions". I'm not sure we've seen that as a sure thing in the mortgage world. I sort of recall a time when we saw lots of bad choices....

This seems like an economic time bomb.

Most homeowners sell within 12 years, so with a 50-year mortgage they’d have almost no equity. They were basically paying rent. At that point, a 50-year mortgage functions more like rent control than equity building.

That matters because the traditional goal of homeownership was to build equity before retirement. Ideally, you combine that equity with appreciation, downsize, and use the surplus to cover property taxes in retirement - effectively reducing housing costs to near zero.

Stretching mortgages to 50 years undermines that. Instead of building wealth, you’re committing to decades of payments with little ownership stake. It flips the model from "own your home" to "lease your home."

And none of this addresses the other big issue: longer terms make homes even more expensive. Buyers focus on monthly payments, so if those stay similar, sellers and builders can push prices higher. Without property tax adjustments, many homeowners could end up priced out of their own homes.