If Customers say no I want the space between me and the next traveler then guess what. You will have to pay for it, Otherwise Airlines at a permanent 55% full will not be here.
There is a price point where they will happily tootle around 55% full making a profit.
The cost per cubic meter of economy class space has fallen 94% since 1960, maybe it needs to rise a little for a change, or does the price only go one way?