In Engelbart's original demo, the users can see each other, talk, collaboratively work on a document, and do together pretty much anything that the computer off

In Engelbart's original demo, the users can see each other, talk, collaboratively work on a document, and do together pretty much anything that the computer offers. The full OS, including the GUI, is intended to be multi-user. Google Docs et al. only offer one aspect of that; all they aspire to do is solve the problem of "collaborative editing of a document". But say we need to work on something that involves listening to audio together or watch a video or use a third party program, we're SOL with Google Docs. What Engelbart's vision aspired to do was to allow people to work together through computers, no matter what the work was. Document editing is a microscopic facet of that.