Let's take som quick math to O'Leary's claims that middle seat free is unsustainable.
According to the Ryanair results presentation their average fare is 37 euro. Add 50% and it becomes 55.5 Still below Easyjet's current of 59 according to the same presentation.
It seems more of a pshycological problem for top brass rather than for any real economic reason, that airlines think they should be excempt from the physical distancing that every other business have to put up with.
Some will always persist on squezing the last of capacity out of both materiel and staff, even at the cost of suffering, for others.