Makie is a actually the front end and there are multiple backbends to choose from. I use OpenGL for interactive but Cairo for publishing figures

Right, but that means that someone implemented the backend interface.

Also, does Cairo support all the features? I thought Cairo only supports 2D graphics, but I see several 3D style graphics in the demos.

I recall seeing something that built on Cairo and provided something that had basic 3d interaction on top of an iterative 2d render a long time ago. So there are projects that do more direct implementations but I'm not sure if they have stable glue to Make yet. This is the sort of thing I hate dealing with directly so I usually just say, " hey that's interesting" and wait for a stable release