When the fed suppresses interest rates and back stops the mortgage market, residential realestate starts to look like risk free treasuries with a ~9% yield.
The only problem is that the rational action with that knowledge is to buy in as soon as possible, with all your cash, thereby making the bubble even bigger. It's a death spiral of inflation.
The "appreciation" is not a given and not risk free at all. Certainly not 9% per year - for how many years do you think that would continue?