Jumping to the extreme of every argument is silly and childish.
In the real world we pragmatically balance conflicting wants, needs and harms to get the best overall outcome. Therefore, while we can have principles a decision made in one context often does not translate automatically to others. Each one needs to be informed by principle but also considered in its own right.
So, dealing with your questions individually:
biological women who are adoptive parents shouldn't be allowed to breastfeed
Before I answer, can you clarify whether you mean women who are already lactating or have induced naturally, or do you mean women taking drugs to induce lactation?
What about women who smoke?
Is smoking and breastfeeding better or worse for the baby than not breastfeeding at all?
should these children be taken into care?
Again this will depend on the context and the degree of harm to the child. Education and support is always preferred. But if a child is considered at severe risk they can and sometimes are taken into care. I doubt smoking would ever be considered bad enough that the harm to the child justifies the harm of removing the child from its mother altogether, although of course that is partly because smoking is still somewhat normalised. (It would be interesting to know how it would be treated if it were a new thing just arising now, but that's a whole other thread)
How do we stop it?
Again context specific depending on the immediate risk, but expectation, education and support would be the preference. In my life I've seen both breastfeeding rates go up and smoking go down not through draconian interventions but through education and support.
Do you see? The black and white mindset says "if we think it's wrong we have to ban if. If we can't ban it it has to be ok for people to choose it". It's a false dichotomy. We can say "this isn't ok, we don't support it or condone it, these are the reasons why, how can we help.you stop it?"
But that's for things already happening. If something harmful isn't yet popularised and normalised and society has the chance to stop it, why would we not do that?