Someone shared this article a while back, and while I don't agree with it, I do think it's instructive. You cannot exactly have an "authoritarian left" get along with a "anarchist left". This video about Hegemony also covers how we can possibly work together.

One, because an authoritarian left looks a lot like an authoritarian right (to an anarchist left). When both the Fascist and the Marxist want to take away your rights, you really need to know which one you're looking at.

Two, even within Anarchist circles, there's some disunity about how to bring about "the revolution". Some advocate for destabilising forces, which would "naturally" cause people to seek freedom. Others think we need to strengthen bonds of society. This, for reasons explained in the article, does not work.

However, even the authoritarian left won't "work" because the end goal for a Marxist is to remove the actual infrastructure of oppression, and like Lenin said, it's not gonna happen; you can't get there from here.

So the real issue is that most of us can agree on where we want to end up, but we can't really agree on how to get there. The Authoritarian left has wet dreams that we'll all somehow learn "the theory" (and frankly given the comments even the commenters in this very subreddit do not know "the theory" and I barely know it), and then something something revolution.

The Anarchist problem is that we explain "the theory" in "common" terms, so it doesn't really sound rational to someone who knows "the theory". Even then, most people are dumb, like ChatGPT dumb. They'll use the right words in the right places but they mostly know that because they're text prediction engines, so they're nominally "anarchist" until the capitalist gives them more bread and circuses for a bit.

In the end, I think a lot of ostensibly "left" causes aren't really "left" at all, so we really need to look at these organisations one at a time. Like the Hegemony video states, this is less about "left" and "right" and more about shared interests.

The one thing that I know for a fact (as an Anarchist), is that the way anarchist and left Organisation works is through social interactions. Sports clubs, Mastodon / Lemmy, families, school friends, uni friends, etc etc. All of these links, if they are strengthened, if we can use them more often than we use the capitalist machinery, are the social consciousness we need. If you eat your neighbours' bread and give them your tomatoes, you're closer to a left utopia, closer to "left unity", and closer to working together against tyranny.

So, we need to fight for third places, we need to fight for places to live, we need to fight for social connections which are peer to peer, not mediated by tech companies. If we can work with that, we can work on a unified left.