I primarily play Adventurer's League, where backgrounds don't come into play much, but I try to make my characters have a good reason for leading an adventurer's life. I would say about half to two thirds of my 70+ characters have living parents, but those that don't still have ties. My oldest surviving character is your standard street urchin orphan, but she has bonds with the other children she banded with to survive as well as with an old harper woman who taught her and brought her into the organization. Another character still has parents alive, and started adventuring because he developed clerical powers and their closest temple was already in good hands with plenty of other clerics and regular priests. A third character, who is also the one that had her backstory come out in play the most, was a halfling rogue who was part of a full run of Princes of the Apocalypse.
It was sheer coincidence that the character and campaign matched up so well. Bree Littlefoot had already been created and had been sitting for a while (my hobby is creating characters and I always have more than I can play), and after a partial run of Lost Mines of Phandelver (where she came in halfway but still hit level 5 by the end) the dm decided to continue the campaign with a different hardcover. I was originally planning to switch characters to a different level 5 that I had sitting around, but when he chose Princes of the Apocalypse I decided that Bree was perfect. She was from Red Larch, and her parents still lived there, but Bree had insatiable curiosity and left home as soon as she was old enough to be an adventurer. Even before that she had been exploring the nearby dwarven ruins, where she had had a run in with the cult of the Howling Hatred and narrowly escaped thanks to stealing a balloon pack (with instructions on it!). Since Princes of the Apocalypse starts in Red Larch, Bree came back home, discovered that the water cult had been trying to track her down by threatening her parents, and got involved in the story that way. She dealt with the threat to her family pretty quickly, surprising her companions with how vicious she was when people she loved were threatened, and eventually finished the campaign and saved Red Larch and her family.
