I have been waiting for the same since PDF got invented. I thought it was going to be an obvious consequence, but I guess it hasn't.

I was hoping this would happen when tablets were introduced. But apparently, for some reason, the idea of infinite, zoomable canvas for interactive objects and annotable documents is alien to most software developers. All the products I've ever seen either a) allow viewing and/or annotating single documents, and/or b) use a very limited canvas with a zoom limit, and/or c) don't allow to put documents in it in other ways than rendered images.

http://web.eecs.utk.edu/~azh/pubs/Henley2018bDissertation.pd... FWIW, for those interested, there's some discussion of the "Code Bubbles" environment which allows arranging working sets on a canvas. (IDK if this falls under "limited canvas" or whatever).

I think a big part of why this hasn't caught on is that the benefits of a layout which maps to a mental model are _generally_ less than the cost of arranging things.