Thirty years ago, at the height of second wave feminism, writers such as Mary Daly firmly defined patriarchy as the root of all oppressions. Popular writing described even the wealthiest and most privileged of woman as victims.
Growing up neuro-diverse with a Glasgow coma score much higher than a potted plant makes it very hard not to grasp what we now call "interesectionality". I can locate one of my own major "aha" moments in my early twenties when I read, in the Myth of the Hyperactive Child, about the way diagnosis of neurological differences vary by race; children diagnosed in the sixties had a much better chance of getting classified as "hyperactive" if teachers perceived them as "white"; other kids ended up with diagnoses of developmental delays or more or less severe cognitive impairments. That experience made it hard for me to accept the idea of a single source for oppressions. My experience of the the dark years of the Reagan administration reinforced this sense. I witnessed the war on drugs and the growth of the carceral state. I saw, and protested, the "Contra" mercenary terrorists and the support for genocidal war in Guatemala, El Salvador and elsewhere. Racism explained these brutalities to me far more directly than anything else.
But if I dimly grasped the reality of intersecting oppressions, I had neither the word, nor any sense of a community that shared my perceptions. I chafed at attempts to fit into a worldview at odds with my experience until I kicked over the traces and ended up more or less exiled for a while.
Since then, of course, the standard view of the "Left" has come close to the understanding of intersecting oppressions. That doesn't make me correct, then or now. Like science, social thought chases after knowledge without ever catching it; like technology, leftist policies seek to improve the lot of human beings without ever completely succeeding.
I believe all these things urge humility, flexibility, and a regard for the human limits of other people. If experience offers us any guide, our most fervently held ideas today may well fall completely out of favour tomorrow. Of course we can, and some of us do, refuse to acknowledge our ideas have changed at all. We have always been at war with East Asia, and we will never be at war with Eurasia again. If, however, we choose to treat our ideas with honesty, it makes sense to acknowledge them as tentative, incomplete, and to show the respect for other people we want for ourselves when, and not if, the limits and contradictions in our own ideas show themselves.