Everyone needs to study postmodernism so that they recognize it when they see it, and can call it out for what it is.
Postmodernism started with the notion that all words can have multiple meanings. Based on this, as you put words together the number of possible meanings becomes infinite. As such, there are an infinite number of interpretations of any paragraph or book.
From this premise, which is at least partially true, postmodernism goes a bridge too far and posits that all of these infinite numbers of interpretations are equally valid. And that is where it breaks down. No – they are not all equally valid. There are only a few valid ways to read a paragraph or a book. There are a great many subtle details in a long work that can be discussed and debated, but each word is chosen for a specific purpose, and words are put together to convey meaning. To throw all that to the wind and say that all meaning is purely subjective – well then why bother writing at all? Just throw the alphabet on the floor and call it a library. Done! That alphabet contains all that ever has been or will be written, and suddenly you do not even need to read anything because everything means whatever you want it to mean, and it is all on the floor in front of you.
The notion that all possible interpretations are equally valid is absurd.
And not to stop with literature, the postmodernist goes further. Facts must for example be realized through imperfect senses. Since our senses are imperfect, facts and truths are only possible through perception, which is inherently subjective.
Again – there is a kernel of truth to that, but postmodernism takes this a bridge too far and posits that all subjective interpretations of facts or truths are equal. From this they go even further and say that, since all facts and truths are subjective, there is no such thing as an objective fact or an objective truth. We each have our own facts and our own truths, and they are all equally valid.
This, like the concept that there is no objective meaning in anything written, is absurd. Science, engineering – the fact that when I flip a switch a light comes on – everything we do when we interact with the world around us proves that postmodernism is completely wrong.
Postmodernism was however not designed to be true, and you can see this in the fact that virtually all postmodernists are also communists, in spite of the fact that if there is no objective truth, there is no reason to pick communism over any other social order and postmodernists should thus be all over the map.
Postmodernism was designed to work around the fact that no society has ever been predicated on equality of outcomes and survived. Societies based on liberty and individualism flourish and societies based on identity politics and forced equality always fail. And that is a fact. Nobody can name any nation that ever emerged into richness that was collective. None. Ever. Every rich nation in the world got that way through free market capitalism, with exactly zero exceptions.
Marxists did a slight of hand in the sixties, by which time their economic arguments had been so thoroughly repudiated that even they knew they were wrong, but like good cultists, rather than accepting that Marxism fails, they gave up on getting the proletariat to overthrow the bourgeoise based on economic oppression, and went with identity groups and power struggles instead. And now our colleges are awash in this.
But none of it is true. Gay people make more on average than straight people. African Americans with college educations make more on average than white people with college educations. The supposed oppression and the supposed power struggles do not exist, except in the heads of people who are not interested in objectivity.
To the postmodernist, all of existence – all facts and evidence – must be rendered obsolete. Marxism only failed based on MY truths and MY facts, and since I am a member of an oppressive group, my facts and my truths are not important.
It is a slick slight of hand, and with it, voila – Marxism lives again, in spite of the hundreds of millions of people who died at its hands in the last century, and in spite of the fact that it always fails with zero exceptions.
If postmodernism ever gains political power, as it is trying very hard to do in Europe and the United States, the world is in very real trouble.
Your premise is correct: Postmodernism was never designed to be true. It is designed to do exactly the opposite of what any belief system is supposed to do: find the truth. Those who are attracted to its siren song seem to have given up on the belief that the truth can be known. We Christians believe God is truth, and belief systems like postmodernism represent just another way man rejects God. In the end, it always comes down to the theology.