Those not in the airline operating or leasing business quite frankly have no idea about various aircraft operating economics....and this includes many (but certainly not all) pilots.
The trend toward large twin engine aircraft for long-haul is unmistakeable, and has been for quite some time.
There are, however, routes that can best be served with 4-engine aircraft, where the cost of the equipment is noteworthy, as not all airlines can afford to use the latest and greatest fuel efficient aircraft.
Some newer aircraft parked by scheduled airlines will be used by charter carriers, to their obvious advantage....767's in particular.
747's (and yes, even the 'ole L1011) will still find useful work, mostly seasonal, the annual Hajj operation is one such example.
Many airlines are eliminating smaller (and less profitable) destinations, and parking the aircraft that serve them.
Expect more of the same in the coming months....it will get far worse, before it gets 'better'.