I mean, eh? The Warrior of Light was able to battle Venat evenly in a friendly spar as well as triumph over several prototypes of Lahabrea's masterworks in Pandaemonium. The Warrior of Light (with of lots of help) also triumphs over multiple unsundered beings, including Emet-Selch and Hesperos. Saying that any unsundered could just "smite" a sundered being with a wave of their hand is overstating things a little.
We don't know what life is like outside of Amaurot and we only have Emet's (heavily biased) narration to go by. The idea that the unsundered world is bereft of any and all conflict is also inherently false, as the ancients developed weaponry, martial arts, and incredibly powerful combat and creation magics. These things do not come into existence in a world free of conflict of any sort. Even Hythlodaeus, who calls himself "pedestrian" by the ancients' standards, is a skilled archer able to use techniques akin to a master bard.
We didn't "barge" into Ishgard. We were invited as a ward of House Fortemps thanks to Haurchefant's glowing commendation and Edmont's trouble saying "no" to Haurchefant. Even then, WoL is shown repeatedly to be incredibly social, possessing an "irrepressible aura of reliability" that gets people to trust them. Alphinaud and Tataru are also fast talkers and charismatic speakers, while House Fortemps and the Scions' previous dealing with Aymeric give the heroes a direct line to the highest ranking individuals in the Temple Knights. And saying, "Well, in reality..." only goes so far in an inherently fictional and idealistic universe. Otherwise Nanamo, Kan-E, Aymeric, Raubahn, Lyse, Hien, and Merlwyb would not all be compassionate and competent world leaders striving to work together in service of their people.