I don’t think much necessity remains in long-developed societies. We revisit the primitive inability to act differently, because now we are able we no longer have the need to be.
We don’t need huge families to benefit us or our tribe, we don’t need children towards any new causes. Whether we do or don’t, it really doesn’t matter - hence the recent birth of existentialism. This philosophical movement would not have happened if it weren’t for widespread settled comfortableness and optional boredom.
Life becomes directed away from the stasis and tameness of comfort, towards distractions and excitments. Love becomes a hobby and an activity: passionate love is on the rise, along with divorce. We have retained the institutions of former times, but they fail because they have not adapted. And we wonder why?
Love is historically dependent.
Its role changes over time. This historical sense: the luxury of putting things in a historical context is also a symptom of a declining already-successful society. Science has foolishly taken an old idea of love, taken it out of context and evaluated it under new conditions - expecting it to still be valid, and emerging with a vague sense of surprise when the conclusion is unclear.
Love is a feeling, but it is quantifiable with chemicals. Scientists just love order, they are very limited right from the start. This is the same instinct that brought about privatisation, the desire to dominate by giving things arbitrary borders. Property, money, chemicals, concepts…