Which makes it ill-suited when you need multiple canvases. Pixijs is amazing, and I mix Pixi, Fabric and regular canvases in my application.

I still would be interested in a use case for more stages. My stagecanvas is the background of the html document. And there I have many layers with different zoomlevels etc

Everything pixi goes there. And can appear exactly on the screen when and where I want. If I ever would have a use case of a second pixi layer above my html elements layer, I can do that. So I am really curious, what else one could need?