I believe the question is not if flying will be necessary. The question remains how much flying and crucially for the full service carriers, in what booking classes.
What puzzled me about this whole issue is how different countries reacted to the Covid crisis and different sectors. Continental europe went to state aid quite rapidly and in very high amounts, Lufthansa for example has now received in excess of 12 billions of state aid from at least three different governments. Air France and Alitalia both receive quite a bit of help as well. And the british aviation sector? Not much help at all from the government. And even in the USA there were massive government interventions for the sector.