I was actually adopted, but remember very little from that time in my life. I lived in foster care, which is another monster all its own. It just breaks my heart that kids are treated this way by the people who are supposed to love them and protect them.
The biggest reason I consider adoptions different is because sometimes kids have RAD, which can cause additional trauma in a new relationship (of course RAD is a sign of trauma in and of itself). You’re absolutely correct that none of us are promised a child free from diagnoses, adopted or not.