Most construction materials can be recycled, why is steel any different?

Most other materials are recycled once to a lesser use. This is referred to as downcycling. Steel can be recycled indefinitely without loss of property or performance. This is referred to as multicycling.

It means steel always has a value, which guarantees that virtually none is ever disposed of to landfill. The multicycling of steel is a self-sustaining system that predates modern appreciation of environmental issues and would continue in the unlikely event that they should ever lessen in importance.