Do you mean to say that collaborative document editing is perceived to be more efficient but that it is in fact not more efficient?

Assuming that is what you meant, that may be true, but for me when working on a document with others there is more to it aside from saving time on writing together. Specifically, being able to see the document as a whole means that I can write sections of text that are more coherent with the rest of the document, and also that I can suggest changes in other people’s sections while we are working on it.

Collaborative editing is also useful when discussing a document on teleconferencing or when we are in the same room. For example if we are talking about a budget and we all have the Google sheet open I can point to a cell or group of cells, say something about it and make a change immediately in accordance with what we conclude, and they can make concurrent edits elsewhere in the sheet for other parts of the sheet that are affected by our discussion.