I think they meant more like they wouldn't have been able to afford the same house 4 years later, due to appreciation of the house, the increase in property taxes on that appreciation, and higher mortgage rates to boot. That or they had a variable APR loan.

The former case happened to us and is how my coworkers and I sometimes discuss the housing market - house values increase so fast where we are, buying a month later would have gotten us an appreciably worse home. A month later, worse again. Prices were increasing 25+% YoY. If we hadn't locked in when we did (Dec 2020) I'm not sure we would have found a place. The mortgage rates seem to not matter because so many of the buyers scooping up houses are older families with lots of money buying investment properties, or whole ass corporations (often foreign corporations) willing to pay 20% over asking, in cash, and waive inspection, to lock out any other prospective buyers.