My city lot here in Richmond is large enough that it could easily accommodate  3 small detached houses, and still have green space.

But city zoning mandates that it's  replacement will be one mega home whose footprint alone can cover 60% of the lot. Due to set-back bylaws - the house is placed as far back as allowed, and the front yard is all paved.

So we have a six bedroom six bathroom house that sells for $3 million, and may or may not even be lived in after it is sold.

By the time council ever gets around to changing zoning (shamed into it by other more creative cities), most of the older housing stock will have been converted to mega mansions and it will be 20 years down the line for the next wave of more sensible re-builds to even be possible.