It's not very long ago that race was considered a "genetic malfunction".

People are still looking for a genetic link to autism.

It is an important point. Our understanding of what is “disease”/“malfunction” and how to address diseases has been changing.

I can see how if we, as society, - gain such immense wealth that taking care of/ providing support to/ humans with DS becomes so easy - arrive to the conclusion that there is no downside in emotional health/wellbeing - change definition of what “living full/happy life” Then parents stop perceiving DS as a concern