Residential landlords are also much different than dealing with corp real estate owners. The terms, length of lease, laws and many other factors are completely different.
Office generally try to maximize square footage, this tends to result in floor plans that are very awkward to adopt into residential use, primarily because the building code virtually everywhere has some sort of "natural light"/window requirement.
This means that purpose built residential high rises tend to be "skinnier" to have more windows per sq. ft of floor space. Not to mention the very expensive changes (hvac, plumbing, etc.) required to support residential use.
If the building code was changed so that the requirements for office and residential use buildings were closer then it would make future buildings more easily convertible between those use cases. It does not solve the problem of the existing buildings however..