*Birth records are not a record of who will live the baby/child the very very most and take it to the park every weekend. It is supposed to be a factual record of biological mother and biological father. IME birth certificates are used to prove your nationality and records for tracing people
Sure, make up some other kind of recording system based upon emotional investment and care giving of adults involved, if it makes you feel better about ypurselves. To what end, I'm not sure.*
If you read the thread, Harvey, you will see that all adopted children have a birth certificate that is a factual record of their biological parentage. They are also issued with a new birth certificate that records their new name. The reason for this is NOT to make adoptive parents feel better about ourselves. It is so that our children can travel through their lives without constantly having to explain why they have a new name, new parents etc. It is also about security: many of our children are in real danger should their original identities leak out unguarded.
For example, I need my child's birth certificate to register her at school. If I only have her original birth certificate, it may be seen by somebody (a member of her extended birth family, perhaps) who could cause her harm. Her original name may also be notorious - perhaps the child of a convicted murderer - and she would need to be protected from that information leaking out.
None of this has got anything to do with me making myself feel better, or pretending that my 'emotional investment and caregiving' makes me a mother. I am her mother, and stunned by how clearly, for some people on this thread, 'mothers' rights' don't extend to me. Perhaps you could think this through before being so gratuitously rude and offensive again.