Secret #1 - Despite Our Extremely High Mortgage Debt, the U.S. has a Below Average Home Ownership Rate
Current U.S. housing policies maximize mortgage debt, not home ownership.

A 2022 OECD study of 28 countries found the U.S. had the 2nd highest percentage of households that owned their homes but still had mortgages. All our mortgage debt hasn’t increased our home ownership much.
Looking at all home owners, whether they have mortgages or not, the overall household home ownership rate was higher in 19 of the 28 countries shown above than in the U.S.
It certainly seems U.S. housing policy is designed to maximize mortgage ownership, not home ownership.
Two of the reasons for the low free-and-clear home ownership rate in the U.S. are our long, 30-year mortgages and our mortgage tax breaks.