Pretty sure they just mean that it’s not as easy as just converting former office buildings into livable space, and that developers are not going to want to pay the cost when it can be cheaper to demolish the building and build a brand new apartment building vs renovating the old office building.

Not only is it more expensive, but a lot of the time it’s just not possible. Why would a developer add enough room in the utility columns to add enough extra space for enough piping to accommodate several times it’s original projected water consumption?

Add in local ordinance such as the increased fire protections required for multi family homes and you’ll begin to see some of the inherent problems people like to breeze over.