Everyone has a different level of risk tolerance. Some people get HUUUUUUGE peace of mind living without a mortgage. Of those who do not advocate paying off your mortgage early, many of them still include "no mortgage payment" in their calculations about when to FIRE. (i.e., I need 25x my expenses for a 4% SWR, but if I pay off the house my guaranteed expenses are way lower, allowing me to safely and confidently RE sooner)
However, here is the flip side of the coin.
Inflation is targeted at 2-3%. Many people (most?) feel the government understates inflation (it has incentive to do so). If you assume a minimum of 3% inflation, or say a minimum of 3.125% inflation -- that means your mortgage is essentially FREE MONEY. As in, you'd be silly to pay it off quicker rather than invest your extra dollars. Because the mortgage company is essentially giving you an interest-free loan (counting inflation), so why would you pay that off when you could be getting a return on those dollars?
Each and every person will have different reasons to be attracted to one of the two viewpoints above more than the other. Only you can decide which best fits your investment profile and personality profile. For some people, the security / peace of mind of no house payment is worth far more than 8% returns in index funds -- those people might go so far as to say, I'm going to be slightly stressed as long as I have a house payment, that stress might take a year or two off my lifespan, no way in hell that's worth 8%. Other people would say, I'm going to be slightly stressed if I know I'm handling my money in any way other than what is mathematically optimal.
As you can see, it's a subjective matter and there's good arguments for both sides. Each person must decide for themselves. Hope that helps you figure out the pros and cons though :)