> Landlords don't create added value. I'm skeptical that it is a necessary service; housing is necessary, but is renting housing necessary? Why would that be?

There are many cases where this isn’t true. Many (most) residents in urban areas are transient. They stay for a couple of years, get married, then move to the suburbs or another city to start a family.

There are a bunch of other reasons why someone wouldn’t want to stay in a location for a long period of time.

Rentals absolutely make sense in this situation.