I think a huge part of what makes face to face (and to a lesser extent, voice) conversations different than text conversations is the simultaneous commitment of attention, so that you can say just one thing at a time and wait for a response (or go on but be ready to be interrupted when something is unclear) instead of having to write whole speeches with anticipations of counterarguments just to keep things going at a reasonable pace.
I think a huge part of what makes face to face (and to a lesser extent, voice) conversations different than text conversations is the simultaneous commitment of attention, so that you can say just one thing at a time and wait for a response (or go on but be ready to be interrupted when something is unclear) instead of having to write whole speeches with anticipations of counterarguments just to keep things going at a reasonable pace.