As you said we are social animals, and bound to be dependent on one another... As per me this dependence has emotional factor also... For me it's nearly impossible to get 100% emotionally detached...
We can't detach ourselves from parents, siblings, or our loved ones. Where there's love, attachment automatically exists this is how human psychology works (but then the question arises, when we should worry about it)
Look I'll give you an example
I've a scale, one end of it has 100% detachment and another end has 100% attachment
Both are extremes so in order to stay sane we need to stay in middle... That's what I meant by good attachment...
100% detachment and 100% attachment both are poison... In both cases a person will end up having mental health issues.