To take a parallel from my own life: When the equal marriage law was about to be passed recently in the country I live in, I was asked "in the name of debate" to discuss the validity of my own family, and my parental connection to my children. Fortunately our kids were too small to realise that in "public debate", division lines were being drawn between members of our family with arguments of "biology" and "nature"
To take a parallel from my own life. I am an adoptive mother. Legally, DD is my very own DD and I have lots of documentation, including a birth certificate, that shows this to be the case. I can make medical decisions about her, take her abroad, choose which school she goes to - exactly as if I was her biological mother.
However, I am not her bio mother (however much both of us might wish that to be the case). We could not participate in medical studies that required mother and daughter. My medical history is completely irrelevant to hers. Moreover, we both of us accept that there was a time when she was not my DD - she had a different name (a dead name??), different parents, and although it's part of her life that she hates to discuss, we all know that pretending it isn't part of her history is unhealthy and unhelpful.
We operate a "need to know" principle, where we tell people such as her teacher but on the understanding that this is sensitive information and not to be shared more generally. If people make the assumption that DD is biologically mine, generally we do not correct them: it is inconsequential in almost all circumstances. If DD were older and needed to apply for a DBS check, we would use the sensitive applications route for the paperwork, like we did with her passport application.
In some cultures there would be some differences between DD and DS (who was not adopted), eg some Muslims do not allow adopted children to inherit from their adopted parents, and I believe it's still the case that if I had a title to pass down, DD would not be able to inherit it. But that's not relevant to us as a family, so again, it is simple to ignore.
Big difference: DD's relationship to me has no impact on other members of the public. No-one is harmed by the fact that she is adopted. And, just to double underline the point, despite the fact that I couldn't love her any more even if she had been, we all know that she was not gestated in my womb and delivered from my body and we do not pretend that she was.
If anyone should be allowed to have feelings more important than reality, I would say that it would be parents and children who are a loving family but without biological connections (step children, adopted children, foster children etc). The world gives us a route to legal recognition, but doesn't erase the past (and nor should it).