The number of aristocrats around the world might be slowly dwindling, but often there crops a need to use aristocratic voices, a voice that defines the nobility, high class and all that is tied to such a social category.
Somebody does not necessarily have to be a member of nobility or a higher class to have characteristics, manners and tastes of aristocracy. Very often, you come up with an exclusive travel location with high-class accomodations, luxury products from flying automobiles to immersive home video/audio systems and complex security systems and you need to reach an audience for such products. That is where aristocratic voices can come in quite handy.
Luxury resorts, high-class art galleries and many other things seem to fit members of aristocracy, but you need to reach those that might not be aristocracy themselves, but have the tastes and deep pockets as if they actually were. Relating the high quality of certain offerings and products can probably reach a potential audience in much easier manner if it is conveyed through aristocratic voices. Of course, sometimes you need to present the idea of high class and aristocracy to a more general audience, and it is a given that you would need to use aristocratic voices.
In English language, aristocratic voices are immediately tied to the extended members British royal family and their tone and manner of speaking. It is clear English -English pronunciation and a tone of voice as if speaking to somebody who is not exactly a member of a higher class. Such voices are often exemplified by such well-known British actors like Maggie Smith and Benedict Cumberbatch, particularly in his role as Sherlock Holmes.