I got a SARS virus flying to Udon Thani in 2019. We were seated next to two thai guys who were so sick they could barely sit up straight. We offered them help and treats because they looked like they were about to vomit.
Plane lands, next day I'm sick. I was laid up for 2 weeks with fever, the shits, and I had a weird spontaneous cough for over 1 month after I got better.
I bet most of that plane got sick, and it was so damn avoidable.
Difficult for the airline to do given the myriad of health privacy adjacents.
It'll never happen becasue everything around travel is to hard to reschedule.