glofish,
If the capacity reduction was unavoidable (i.e. no extra airport slots), a 777X would have to be about 33% more efficient than an A380 to generate the same profit per flight as an A380
I very much advise you go over such numbers before you make a fool out of yourself
Fair enough. The point I was tying to make is that what matters most to a business is overall profit. Shareholders don't like profits to shrink, and things like profit/seat means nothing to them. If an airline is making an amount of profit by flying an A380 on a slot constrained route, then replacing it with a different aircraft type has to raise the same (or more) profit per flight otherwise the shareholders get grumpy.
And because of the disparity in seat counts, getting a fully loaded 777X (406 seats?) from A to B has to make you about 33% more profit per seat than flying a fully loaded A380 (544 seats?) over the same route. I simply can't see the 777x achieving that. One can easily see why Emirates, who have some slot constraint problems and fly A380s at quite high load factors on those routes, are keen on the A380, a stretch, and especially a neo.