I went on a ski trip with my friends 4 years ago and one guy was pretty excited that he'd paid off his mortgage. This was 2010 and there wasn't much confidence in the stock market. I told him that I had the money to pay off my mortgage, but I was keeping it invested and I felt like I had a secure job. We discussed it at length, that he now had hundreds of thousands tied up in his house and he had no plans to take it out.

Fast forward to now, I have been able to refinance twice and unexpectedly improve my cash flow, my investments have been fantastic, and I've been able to make use of the interest deduction to further offset the interest rate (2.875% 15yr). I also see a mortgage payment as a budgeting tool - the prinicpal payment is like putting money in the bank (where the only 'real' way to withdraw is to downsize) and it keeps my budget tight. If I ER this year, I will most likely pay off the balance out of all of the extra proceeds in the stock market, but it takes a lot of foresight and planning to capture all of these benefits.

My friend ended up moving about 2 years ago, and has a mortgage on his new house, although he moved to a lower COL area with a more secure job. I think our conversation, and the outcome over the years, was pretty convincing.

But to each their own, I have seen this seemingly straightforward discussion come up over and over with very little progress. Maybe someone needs to create a mortgage payoff simulator using historical returns and mortgage interest rates, (with an option to refinance at any time for the cost of, say, a quarter percent of the going rate, during the life of the loan), with a shadow line of slowly investing that same P&I payment monthly, and show that the probability of coming out ahead financially over, say 30 years, or even 15 years, is 100%.... anyone, Bueller?