I've written previously about Western culture's dual inheritance, moral reasoning from the Bible and logical reasoning from classical philosophy, especially the proto-science of the ancient Greeks, which later became natural philosophy and then turned into modern science. The two together form a rich patrimony. We did not always make the best use of it, but still achieved many things that were remarkable.
We are now in the process of replacing both reason and faith. One of the replacements is Expedient Truth. This is the stuff you know is true because it serves the Cause. The corollary is that you know you are to disbelieve ideas and evidence that do not support the Cause. What cause? That varies.
The other replacement is Relative Truth. These are the things that are true for you and not for me. Your truth, not necessarily my truth. Truths like this differ from Expedient Truth in an important way. Relative Truth is of no use if you want to convince me to do something I do not want to do. By the same token, when I explain the reason why you should do something, or stop doing something, that's only my truth, not your truth. Who am I to impose my truth-concept on you, after all?
The same limitation does not exist for Expedient Truth. There you only need to convince me that the Cause is right and I am then supposed to assent to anything, no matter how preposterous, that would be helpful to the cause. If I don't think the polar bears are in any particular trouble, or I do think that the world warmed up substantially in the medieval era and then cooled, that isn't simply a matter of my truth, I'm a "global warming denier." I must want the earth to die! Expedient Truth is for compelling belief or obedience and Relative Truth is for escaping both.
Expedient Truth inverts the classical logical ideal. Rather than observing the facts and framing your opinions on that basis, you first frame your opinions and then select your facts. You support your position with shame and ridicule directed against naysayers. Relative Truth is an attempt to relegate all non-Expedient truths to the status of matters of taste, about which no meaningful disputes can occur. This certainly simplifies discourse. It is now a matter of parroting insults about those who disagree with you (Expedient Truth) while ignoring the substance of what they say (Relative Truth).
I do not think these new truths will prove worthy replacements for the truths we had before. They will not lead to moral or material progress. They seem directionless in the long term, tending to random changes in thinking with changing political fashions and far too easily steered by propaganda. When science becomes agenda driven it no longer goes its own way, advancing as it lists when new facts are found out. When morality is merely a matter of taste and private judgment, meaningful moral dialog must cease: There is no common ground for discussion.
If these new truths are indeed truth as some perceive it, there is little the rest of us can do about it. We can warn the people who think this way but that is only our truth. We can critique their reasoning and its outcomes, but if we do that we are global denier misogynist homophobe racist racist racist nativist speciesist reactionary running dogs of capitalist imperialist expansionist colonialist aggressionism--or something. Anyway they will not say anything nice about us.
No: When people are convinced by the new truths, the only thing that dissuades them is disaster. Disaster reliably follows upon abandoning a stable basis for moral and practical judgement. Sometimes not even that does the job. There are still some Russians who long for the good old days. If you were supposed to have an opinion you were issued one.