The Lord was merciful (Genesis 19)

“When Lot still hesitated, the angels seized his hand… and rushed them to safety outside the city, for the Lord was merciful.”

It would seem there wasn’t much worth saving where Lot and his family were concerned. Lot had made his home in Sodom, and had found a way to coexist with people who were unspeakably wicked.
Even when judgment was imminent, and Lot was commanded to leave the city, he hesitated to obey.
And yet, the Lord was merciful.