I believe social and cultural norms changed over last century at least in West and this trend is mimicked by so called "developing countries" making parents isolated, tired and frustrated; add technological burden for kids not spending their developing time running around exploring world but be hooked to single pair or worst single adult because of all the danger increases amount of stress average parent has to cope with.. add to this how unnecessary stressful in some aspects modern became.
I would highly recommend "Why We Sleep" by Matthew Walker to get academic insight to latest research related to sleep and basic understanding what sleep is. There is a good touch on how other species sleep; and why having a nap during a day is beneficial in improving intellectual and physical capacities!
Sleep health benefits are definitely underrated in modern society..
Based on my understanding of the topic I sympathise the research narrative to move to polyphasic sleep cycle to COPE with sleep disorders I do not believe it is adequate sleeping routine to any healthy individual and doing so can be harmful to health!
And from personal note as a parent raising second infant I can confirm that having segmented night sleep over long periods of time is most de-humanizing experience with real mental threads.
I believe social and cultural norms changed over last century at least in West and this trend is mimicked by so called "developing countries" making parents isolated, tired and frustrated; add technological burden for kids not spending their developing time running around exploring world but be hooked to single pair or worst single adult because of all the danger increases amount of stress average parent has to cope with.. add to this how unnecessary stressful in some aspects modern became.