Corona virus and antibody tests before boarding should resolve the issue ( I understand they now have "quick" tests for both), allowing to fully populate the airplanes seats safely...
If the tests are reliable enough and accepted by the destination authorities just factor the costs in the ticket price...
It will the cheaper alternative, also explore the possibility of government subsidies for such tests.
And voila the airline industry is saved !! (WELL.... easier said than done) to be continued...
Of course there is always the possibility of being "freshly" exposed at the airport counter or the taxi
...