It's my children that I worry about.
They're boy/girl twins, now 25. My daughter is in the process of breaking up with the boyfriend she's lived with for the past two years, and moving back home to re-settle her life. She has a career, and wants to get married and start a family sometime soon. Her boyfriend is a great person to be around and she adores him, but... he doesn't want kids (and is actually freaked out by them). He doesn't want marriage. And he can't keep himself organized enough to uphold his financial/personal responsibilities in cohabitation. So where is she going to find a potential partner who shares her social values, and wants a life partnership and a co-parent, who can uphold their responsibilities? She doesn't even know where to look.
Her brother lives at home, and probably always will. He doesn't have a real career and can't adult well enough to live on his own, even if he had to. He has never been on a date, even, and lives for video games. What happens if he looks around one day and suddenly feels lonely for a family other than his aging parents? With no financial substance or adulting skills and no romantic experience, he's not much of a catch for partners his age. He'll have to take more family/household responsibility as he gets older, and that's fine, but what happens when his parents finally pass away and he's an old man?
As a parent, these situations worry me greatly.