As I, and @Aldarc, and I think maybe others, have repeatedly posted: this is not a general truth about fantasy as a genre. And it appears to be belied by the Noble background, which describes its feature thus:The only thing that makes a noble special is a title, a sense of entitlement, and the social constructs of the society they live in that respect the title. Take them out of the culture that respects that title and they are no longer special.
Thanks to your noble birth, people are inclined to think the best of you. You are welcome in high society, and people assume you have the right to be wherever you are. The common folk make every effort to accommodate you and avoid your displeasure, and other people of high birth treat you as a member of the same social sphere. You can secure an audience with a local noble if you need to.
(Emphasis added.)
EDIT: As the Dreadnought host shows us, of course, sometimes a sense of entitlement is enough. But in the context of D&D that looks more like the Charlatan background.