Stress levels. It's a huge mental burden removed when you pay it off. It gives financial freedom of some sorts. My plan was to pay off my house and quit my job and find something easier on my body. Paying off my mortgage allowed me to financially be able to take any position I wanted even if it was a pay cut. It was about 30k but it was less of a burden and my quality of life is substantially better. At 47 yo it gives him the financial freedom to do whatever he wants. He already has a mm plus in retirement. He couldn't retire early of he wanted without the worry of a house payment.