Scott Burn's article, "In the game of long-term investing, the house wins", makes for a compelling read.
Essentially, once your home is owned free and clear, it's difficult to match the return you get from that home with other sources of investment revenue.
The amount of "imputed income" your home gives you is tax-free, continually inflation-adjusted and is as important as Social Security retirement benefits for many retirees.
As Mr Burns says:
The more we own free and clear, the better off we are because free and clear ownership delivers valuable services without the burden of income taxes.