Short range could be explained by airflow rates in most buildings being near nil. Someone talks in one spot, and pathogens hang around that spot in the air for many minutes.
With say 10 air changes per hour (injecting at the ceiling and extraction at the floor), and a 3m high building, you can expect airflow downwards at about 1 cm per second. That means there is perhaps only a 30 second window for a particular pathogen to hit someone else's nose before being pulled to below face level.
It's not nil, but I think that would lower transmission rates by a sufficient factor for COVID (and many other diseases) to become extinct.
