Thank you for this question. The FWB concept is an enigma to me being a baby boomer. I would hope a friend would still be there when a mortal wound is encountered. Such as during the AIDS epidemic when women, especially gay women, stepped up to nurse those who were infirmed. It completely alterred the gender segregated gay population. currently gay women's bars are nolonger common as gay men embrace their sisters & the straight (cis-gendered) world accepts diversity in this country. So I am looking forward to see other explanations for the FWB phenom.