From my experience, I’m pretty sure the decision to pay off a house is not an either/or decision for most of the 21% mentioned in the OP.

I would venture to guess most of the 21% have plenty of cash/investments/pensions, etc. to cover living expenses/retirement, etc., AND pay their homes off.

Some of us bought our homes/investment properties for relatively nothing, compared to today’s pricing. Others, who purchased their homes fairly recently, as some on this board have done, have come in with cash to purchase million+ homes–even at today’s prices–so it is conceivable that both can be achieved.