a/c have shrunk over the last few years
once upon a time LGW was a line up of 747 DC-10 and Tristars now its 320 and 738 in the main with many long haul oceanic flights conducted by narrow body types such as 738 and the 320/321 especially now on many USA transcontinental flights and from UK provincials
the old 757 is still seen on legacy airline Long Haul oceanic use by many carriers UA AA EI Iceland
this is really a retrograde step to go to so much narrow body use
the 738/or MAX and 321 are no match for a 757 or 767 which airlines today are trying to emulate
Boeing have lagged behind thinking they can keep on stretching the 737 to get it doing missions which are way beyond its original game plan
as for airbus the 320/321neo family again merely gasps at grabbing abit more range in a narrow body that was never designed for going over the pond nor transcon/Hawaii