30-40 plus years ago there was a social stigma to being an unmarried mum. There was little to no financial help in terms of benefits. There were more babies and very young children up for adoption then and the likelihood of the babies/very young children having other problems such as emotional issues or damaged in some way such as through drug use during pregnancy was not as great as today.
Today, as there is no social stigma to being an unmarried mum, and there are far better benefits to enable a mum to cope financially there are far fewer babies/very young children who are up for adoption. Those children (any age) up for adoption are more likely to have had more time with their unsuitable birth parent(s) to be emotionally or physically damaged and more likely to have been damaged due to drug taking during pregnancy.
AIBU to think that adopted parents 40+ years ago had less problems with their adoptive child than adopted parents of today? AIBU to think just as there are fewer babies/very young children up for adoption, the above means there are fewer adults prepared to adopt a child too?
Let me just put on my hard hat and bullet proof jacket on.