GP said that we do have a society right now where economics is a eugenic factor. Please name one instance of the pattern you described in society today. I'm not aware of any tax on generic markers.
Additionally, you will have to pay the full price for any treatment that's outside their recommendations, this often turns out higher in absolute prices than in any US hospital - even though the people are much poorer.
Then once an unhealthy child is born they often don't get the full benefits of socialized healthcare as they should according to the constitutions, the administration will say "the system works in a different way and you went outside it, so you need to take care of it yourself" and the parents are forced to pay for treatments and medical equipment by themselves because what "the system recommends" is not nearly enough (we are talking about US$ millions of additional out-of-pocket expenses in some real world cases that I follow locally). That could be interpreted as a form of tax too, especially since you are forced to pay mandatory health insurance in most of these countries.