But this happens because we don't live very long currently. So we prioritise using the time we have to build material resources so that when (if) we have a chil

But this happens because we don't live very long currently. So we prioritise using the time we have to build material resources so that when (if) we have a child we can maintain standard of living. If you were assured to live even 100 years you could spend the first 50 creating a high standard of living and the next 50 raising children within that standard.