This is where the line of thinking goes in the opposite direction for me because you've gone 100% the other way!Life's lessons,
Always pay the mortgage first and always overpay if you can. (think how much money you may have saved overpaying when rates were cheap).
Never use expensive credit to buy fast depreciating assets, holidays, cars etc.
I cannot think of one thing we bought on credit excepting the house.
I've been given literally hundreds of pounds by credit providers because I've spent on credit cards and paid it off the same month, and I've got a kitchen on 0% interest for 5yrs, which I'll pay off before any interest is accrued.
However, I also share your view in that overpaying a mortgage is valuable to a lot of people, and I think that sometimes the thought process on whether it's a good idea to overpay or not is a bit too "binary".