I agree that office has a nice granularity there, but the UI is not very good. People don't understand that they have to share a specific link to a document and

I agree that office has a nice granularity there, but the UI is not very good. People don't understand that they have to share a specific link to a document and they can't just copy & paste the address of the page they are seeing ... Link shared -> "don't have permission" -> sender replies confused that the link works for him is an exchange I have seen way too many times.