Plane Sailing?

A study, carried out in the USA, is seemingly quite reassuring about potential Covid-19 transmissions, whilst on a traditional passenger air flight (https://news.sky.com/story/coronavirus-revealed-the-risk-of-exposure-to-covid-19-on-a-passenger-plane-12105228). Admittedly, the study was only carried out on 2 types of Boeing planes and assumed that all the seats were occupied. It was also assumed that every passenger (and flight attendent?) safely wore a facemask for the entire journey. One might question whether this is realistic for babies and people with phobias. People would also presumably eat and drink on a long flight. In the study, passengers didn't move around the cabin (what about using the toilet?). It was estimated that, if all the previous criteria applied and only one passenger had a Covid-19 infection, the rest of the passengers would have to be on the aircraft for 54 hours to receive a critical viral dose. It was also pointed out that the air was changed on these 2 aircraft types every 6 minutes. It all sounds very good but the idiosyncrasies of the many humans (as well as there possibly being more than 1 Covid-19 positive person on the flight), make this an overly simplistic calculation. I don't think passenger flight is as safe as implied and there is the added problem of moving the virus around the globe. One should also note that airports are likely to be locations where viral transmission is quite likely.