Seller financing stays niche because it needs two rare things at once: a seller with the equity to carry the note and the willingness to act as the bank. The equity side exists. A substantial share of U.S. homes are owned free and clear, so the pool of sellers who could carry paper is real. Willingness is the harder constraint, because carrying the note means giving up immediate access to the sale proceeds and taking on real prepayment and default risk. One of us lived the prepayment side decades ago as the buyer: a condo purchased with seller financing, a modest fixed rate, ten percent down with no mortgage insurance, from an owner who wanted the interest income for tax reasons. When rates fell a few years later, that buyer refinanced away, and the seller was unhappy to lose the long-term income she had been counting on. A seller carrying paper needs to go in with eyes open. Nobody can promise where the trend heads. As more owners sit on free-and-clear or very-low-rate homes, seller financing may tick up modestly, but the willingness constraint makes a large shift unlikely. If a seller-financed deal is in front of you, it is worth structuring carefully with people who have actually done them.