Not only that, the fact that the person on the other side of the conversation does not have any clues as to what is happening and as such is wont to keep on bla

Not only that, the fact that the person on the other side of the conversation does not have any clues as to what is happening and as such is wont to keep on blathering while her conversation partner really needs to focus his attention on that slippery slope/crumbling ledge/onrushing traffic/deer jumping in front of the car/rushing river/person in distress/...(fill in the blanks)... makes telephone conversations much worse than those between two or more people in the same location.