The 797 enjoys a 40 years technology advantage over the existing single aisle competition, it should be not depending on the container size to beat the competition with ease.
You forget, that it needs to be competitive against same-tech-level narrowbodies, that will arrive a few years later. Your argument is as flawed as Airbus saying in 2000: the A380 will enjoy 30 year technology advantage over existing VLA competition. And yes, it did beat the 744 and even the 748i with ease. But not the upcoming same-or more-tech-level near-VLA competition.
Would not a same-tech-level launch of a 200-250 seat mid-range NB in 2030 (be it from A or B) shorten the 797s competitive life so much, that the overall market outlook becomes questionable? In 2030 the 797 factories would just have reached the planned output rates.
However the logic is outlined by 2175301 and fmrCapCadet above; and additionally Bigjku previously:
The background is as I (among others) have speculated about over the years, EG that BA would do an effective repeat of the 767/757 "sibling" development.
Easy to say: very very hard to do, because as Bigjku has outlined, the transition from the MAX will be hellishly hard. In particular, in a perfect world, the trick is to wring the last drop of juice out of the MAX line (737-8 in particular); then to immediately transition to the NSA.
Can't be done perfectly, of course, as (again) Bigjku outlines.
But you can do pretty well if you already have in production a small 2-aisle with all the required systems basically already in volume-production as well as there being minimal changes required to EG empennage, nose-section etc etc.
So then you then have the best possible accelerated start into the NSA production/speedup task. (**)
But meanwhile BA are very very very concerned that the NMA (797) IS ALSO
PROFITABLE ON IT'S OWN MERITS.
Hence the delay.
And consequently heavyweight, high-profile contributors on this site (Revelation EG) have long been concerned about the NMA business-case.
The BA strategy seems to recognise this; but if they can make the NMA work,
then ]BA has:
1) a profitable niche all to itself, as well as a dynamite fleet-selling proposition for the Sales staff; and
2) a perfect lead-in to the NSA.
So then (in the unlikely
absence of any response from AB whatsoever), then AB will be faced with an NMA which will dominate it's own niche but which will also give substantial leverage to the BA Sales Staff, IMHO, when marketing their next-gen NSA; as well as an accelerated start to the NSA changeover/rampup.
If this has been discussed here, then apologies; I haven't seen it.
My point is that BA are steadily making the point that the NMA will NOT be a new hi-tech "Moonshot".
WHICH MEANS THAT THE NSA WILL NOT BE A MOONSHOT EITHER!
So much for all the (endless) posts to the effect that there will be NO NSA launch until 10% - 15% - whatever improvement is available.
But that is for another thread!