"we are left in a position where topics of critical importance in
medicine and environmental science can be thrown into doubt by
opponents with political axes to grind"
We were going to be in that position anyway. Look at US politics on covid & climate change - nothing to do with Structuralism.
I would argue that thinkers grouped under 'postmodern thought', including structuralists, shouldn't be thought of as advocating relativism, but as advocating attention to discourse and pursuasion. Discussed here:
Why is post-modernism so often equated to Relativism, are there any responses in postmodern philosophy that challenges this?
We already know social discourse has fragmented largely along partisan lines, to the extent of people living in different realities. It's not the first time it's happened, in WW2 ideology was also weaponised, and a with-us-or-against-us tribalism used to coerce people into accepting realities and narratives. Putin has been doing it in modern times.
Like aspiring to Socratic Dialogue, an adherence to scientific standards of verifying reality is a great ideal. But even there we find politics: apparently the era of tobacco-science started with scientists trying to undermine the idea of nuclear winter, because they felt it undermined US nuclear options, and the same group moved on to climate change denial. You can't just dismiss people for having bad motives, they have to be taken on not just with evidence - but also with rhetoric. We can wish society was otherwise, but we don't get to be like Socrates and ignore people with no interest in the truth, public opinion matters, and all our futures depend on it. We need the tools of observing cultural change and discourse, not simply appeals to the one reality with best evidence as modelled by science. People don't choose the best evidenced reality, they choose the most pursuasive, and that depends on evidence, but also how that is put to them.
There is an inclination in Structuralism to see in it the explanation for all human behaviour, in linguistic and cultural conditions, and that is I think over-reach, in a crucial sense.
"Freedom is neither a legal invention nor a philosophical conquest,
the cherished possession of civilizations more valid than others
because they alone have been able to create or preserve it. It is the
outcome of an objective relationship between the individual and the
space he occupies, between the consumer and the resources at his
disposal." -Claude Lévi-Strauss, “Tristes Tropiques”, p.145
On the face of it I find this hard to reconcile with the heritage of Existentialism, and Sartre's insistence that properly understood freedom cannot be taken from someone who does not give it:
"no limits to my freedom can be found except freedom itself or, if you
prefer, that we are not free to cease being free" -Being and
Nothingness: an essay on phenomenological ontology, 1943
I would argue this denial of a deeper reality to freedom by Levi-Strauss, misses that the core purpose of philosophy since Socrates has been to unbind ourselves from the rhetoric of Sophists, by dynamically cultivating wisdom, as the capacity to act from the centre of our own concerns and know where that is, separate from those aiming to pursuade us without regard to our interests. That is, gaining wisdom is exactly the tool to make our own choices more freely, and not be bullied or lied into them. Of course, that 'integrated self' has many layers, and Functionalist tools can help look at them. But I think it's critical to acknowledge there is a direction of being more free in our thoughts, away from 'bullshit', pursuasion without regard to truth. And I'd go further, that science is founded on that premise, on Socratic dialogue, combined by Plato with the Pythagorean math-cult into the Academy, and academia.
Russia is experimenting again with unlimited propaganda, of the kind that led to Lysenkoist agriculture and famine, and even trying to claim that as a success. Some social structures of truth-making, succeed in their own or short terms, but at costs. We might say, they involve intelligence, but not wisdom - they don't involve acting from the integrated centre of concerns, they involve contradictions and the potential to be self-defeating. Having the bests scientists free to think, is just much more effective than propaganda. In the US the anti-climate-change-action lobby feel they are succeeding, but they will see future generations there pay a massive price for their small temporary revenues - they are not being wise.
So, I would use Structuralist ideas like Durkheim's structural-functional picture of how societies maintain their cohesion, to look at realpolitik and the dirty business of cultural discourse and social change, to try and understand how to impact the world for the better, or simply interpret how society is changing. Like, we can look at pursuasion through first finding where there is common ground or shared values, or I like Haidt's Moral Foundations theory for looking at the undrecognised (by the left) role of sanctity in maintaining social cohesion among those who feel under threat. I enjoy Zizek's use of Lacan to unsettle assumptions about our times, and sometimes helping to feel a little more sane about them.
But I would prefer to discuss with those committed to Socratic Dialogue, and to compare evidence with those trying to find the best hypothesees to account for them, because that is the wiser path, and even if the fruits of those discourses don't pursuade people now, in the long run if they truly involve acting from the integrated centre of concerns, their wisdom will speak for itself. We live in an age when many societies are becoming less wise. It is not enough to just disengage. We must seek to knock down Sophist arguments, without becoming them. We are animals, and our societies have animal-spirits, that must be understood too, by the wise.