Thanks for your reply. As I said, I adopted under a very different system to yours. Yes, the birth parents will have been convicted of a serious crime against the child. Yes the birth certificate does remain intact. Yes an adoption certificate is issued. Yes we are named as parents on that certificate - that is for us, not the child really, as a legal convenience when accessing medical services and going on holiday so we don't have to ask the birth parents' permission (guardians have to, and trust me, that isn't a foregone conclusion). Yes an adoptee remains in contact with any people they had significant relationship with prior to adoption, birth or foster family (at least those it is safe to do so), and the idea is that they should feel part of both families. They will need a new family because there is no member of the birth family who can provide that support - if there was then they would be the guardian and the child would not be adopted. The number of children adopted in every local authority each year can be counted on one hand (well sometimes two hands). Children are not taken from birth families to be adopted. They are only adopted if foster care is judged to be not suitable, and that can be many years after leaving the birth family home, with no hope of ever going back as a child. There is a period of maybe several years called 'placement' where the 'adoptor' is a guardian, and the child effectively decides between foster care or adoption. Not entirely foolproof I agree, but not insensitive to their needs.
No one is pretending. We are conscious of our status in the child's life. Their identity is their own. Your identity doesn't get set by external factors, and it isn't innate at birth, it is up to you how you identify. Many adoptees will lead a life once adult between the birth family and the adoptive family if they wish. It is a bit odd to suggest that no one would want to spend their own time and expense bringing up a child who is not related biologically if they weren't a parent. Why not? Children aren't 'owned' by anyone, they have rights of their own and that includes the right to be safe. Guardians (remember all adopters start as guardians), independent visitors, long term foster carers and step-parents (who are not parents under UK law) do exactly that and no one blinks an eyelid.
Don't get me wrong, there's plenty we can do to improve it, but it isn't quite the tragedy that is often portrayed as. And yes, my son may have a different view than that, and that view may change as he gets older. It doesn't change my feelings about adoption or about him. If I didn't think I was doing the right thing by him then I wouldn't have wanted to show him my commitment by adopting him. Two perspectives can co-exist and both be true for the person who holds them.