Where I live, people are blocking the construction of new apartments because the cost of the new ones is a bit higher, 10%-50%, than the average existing apartment.

The idea behind blocking the new apartments is that "new expensive apartments don't help anybody" and people get very upset that the new housing is going to the type of person that can afford to pay slightly more for the newer apartment. Rather they would prefer that new housing is only built if it's cheaper than existing housing.

So when housing does get blocked, the existing landlords demand the higher new rents that those wealthier people pay, driving up the overall costs on old apartments. The poorer people get displaced, the wealthier people have housing but worse housing, and the only people who are better off are the landlords of the older apartments.