I think it is in the heart of an individual.
Like angelina jolie, she adopted different kinds
Like sia, she adopted 2 fully grown 18 years old. Well now she's a grandma cuz one of them just pops out twins. Judgement free zone here.
Lets say if you grew up in the mother land and your good neighbor is a good neighbor to your folks and your whole family are in america while they are still stricken by poverty there. You wish you can save the whole family but the most you can do is adopt one of their baby. At least this kid can grow up to be someone special and if they still have the heart to help support their own family, they can do so once grown.