The opportunity cost over the longer term, and considering the alternative of investing in shares, has been greater still. Twenty years ago mortgage rates in Britain were not much higher than they are now, at around 5%. Even with a once-in-a-century financial crisis looming, buying stocks rather than making early mortgage repayments would have paid off handsomely. Since the start of 2005, measured in pounds sterling, the msci World share index has generated annualised nominal returns of above 10%. Had your mortgage rate stayed the same for the next two decades (though in reality it would have fallen), paying off £1,000 ($1,250) in 2005 would have saved a respectable £1,800 in interest. Investing it in a global share-tracker fund would have made a profit of £6,500, however.
https://archive.is/2025.02.13-110046/https://www.economist.com/finance-and-economics/2025/02/13/why-you-should-repay-your-mortgage-early