Boston, a city of fewer than 1 million people, is surrounded by layers and layers of suburbs linked to the city by subways, ferries, and a commuter rail. The suburbs’ opposition to a new state law requiring them to zone some land for apartments illustrates why U.S. rental housing is scarce and rents have soared. The sprawling town of Hamilton, with 8,000 residents, told The Boston Globe that rental housing will “destroy the well-being of our community.” Other municipalities warn their schools, infrastructure, and police and fire departments will be overwhelmed by population increases or that they don’t have enough land to accommodate multifamily rental properties. Not all of Boston’s suburbs are opposed to building more multifamily housing. Before t…