just deathwing, eh? seems like selective bias.
keep this in mind. we'll come back to it.
this is exaggeration. first of all, we have to understand and accept that bahamut is being used as a convenient excuse for redesigning the game world, and he serves that function admirably. the dev team have even specifically commented that he mostly only messed up mor dhona and coerthas (though not *only* those areas- they just saw the worst of it). other places were completely untouched. all of thanalan, for example. other areas which were changed without being attacked were explained by the gravity from Dalamud's descent reshaping the land. while you could attribute this to bahamut, i don't think that's very fair considering it's entirely incidental.
and let's go back to your 2.5 years comment about deathwing, which is accurate enough. but look at the state of ARR- it appears just 5 years after the events ending 1.0. you're telling me he succeeded in destroying the world, and we rebuilt it all in just 5 years? i'm not buying it.
pretty sure devs commented on this, too- only players participating in the battles ending 1.0 were teleported away into the future. other people who were far away from the attacks, in lands which were untouched, were subsequently untouched themselves. not only is this evident through the simple fact that the chocobos all seem alive and well, but in ARR there will be a distinction between legacy and non-legacy players, where the legacy players will have slightly different dialogue and story than non-legacy, referencing the events ending 1.0. non-legacy players will get something a little different, and a little different flavor text from NPCs.
i think it's easy enough to assume that new non-legacy adventurers aren't 5 years old, so for them to exist at an adult age 5 years after Dalamud's descent, but be completely unaffected and uninvolved with that story arc- this seems to only underscore the implication that they were simply in different parts of the world at the time of those events, and were thus unaffected. unless they just appear out of the aether as fully functional adult beings? but that would ruin immersion, wouldn't it?
and here we disagree on one point, in spite of agreeing on another. bahamut does seem to be the more powerful of the two, and many have covered perfectly valid points underlining why- but as has been pointed out several times now, bahamut also failed to destroy the world, and didn't even really destroy that much (again, unless you also credit Dalamud's descent with changing the landscape, but wouldn't that credit better belong to Darnus?). yes, some areas of azeroth were unaffected, but most of those were expansion areas far removed from deathwing's immediate reach. the entire vanilla azeroth was changed.
now, that said, it definitely took him a lot longer to accomplish that in relation to what bahamut did in a few seconds- so again, the scales seem to obviously tip in bahamut's favor here. so why go to so much trouble to disagree with certain points when i agree with the end assessment?
because the avenues people take in arriving to that assessment are often biased and inaccurate. and in the end, what's the point of a discussion board if people aren't free to disagree with particulars, whether they agree overall or not? because then it's just a bunch of people talking for the sake of talking, saying whatever they want without considering anything else, and that defeats the purpose of the discussion part of the forum, no?