I thought the political compass was itself just a popular perspective? It's is a gross oversimplification of the ideas involved. Find me two leftists who even agree on what's the farthest left.

I'm not sure it is. Like, yes, it does exist in the Left/Right, Auth/Lib political compass, but that's just a model. The stance has some inherent contradictions.

And so does Right/Lib, for that matter. "Fiscally conservative/socially liberal" is a nonsense position, and those taking it tend to just be conservative in practice.