Why not allowing adults to their adoption records instead of open adoption?

I think it would be better to allow people who have been adopted access to their adoption records when they are an adult. I think it is a better option than open adoption. I think a young person should grow in the home of their adoptive parents without having to interact with their biological parents. I think it will cause less confusion for the child. Then, when they are an adult, and not before, the child can decide to contact their biological parents. And I'm not talking about SOME records. I'm talking about names, addresses, anything the biological family wants them to know. But the choice is up to the child and not the biological family. I think the ties between biological relatives should be severed as they are being raised by the adoptive family. I think it's fair to the adoptive parents and better for the child because it promotes stability. I don't think it is appropriate for the biological parents to have it both ways.