I was looking outside my window last week as 2 sisters were going door to door on my street. I could see them walking slowly up to a door and knocking once and not staying more than 10 seconds. No one came to the door, so they left for the next house. They were walking so slowly and they had the same results at each house.
It must be really discouraging for them to see no results. Once an elder told me that 30 years ago, people talked to them at each door. They had good discussions, and bible studies started.
Their time is up.