The main point is to minimise the risk of infection of others. Masks do that by limiting the amount of virus you spray info the environment with every breath. The longer you have the mask on, the fewer virus-laden droplets get out, the lower the viral load is for everyone around you.
So to answer your question, yes, keeping the mask off the whole time would have been measurably worse than keeping it on before and after eating. No, getting a meal at an airport is not ethically wrong even if you have to take off the mask to eat and drink. Wearing the mask for as long as possible is the right thing to do because it offers the best chance of not getting other people sick; taking it off to eat balances your needs with the safety of others.
If everyone masked like this (even if it was just when they know they’re sick, instead of always), many fewer people would get sick when they go flying.
Well, science has also shown that environments devoid of pathogens tend to produce people with allergies and autoimmune disorders. So maybe if everyone wore masks and nobody ever got sick, we’d have a society of people with allergies and autoimmune disorders.
Masking doesn’t render the air “devoid of pathogens”, it just reduces the amount of pathogens you’re spraying into the environment while you’re contagious, and provides some filtering of the air you’re breathing through your mouth and nose.
Our immune systems will still get “exercised” by fighting off the pathogens we do encounter, but they won’t necessarily be so easily overwhelmed since we won’t be constantly inhaling more and more virus while our lymphatic system is busy fighting off the replicating viral bodies that have already gotten in.
science has also shown that environments devoid of pathogens tend to produce people with allergies and autoimmune disorders
It’s actually the other way around, with viral infections being one of many causes of autoimmune diseases.
