They’re geniuses at marketing. To take their lack of traditional talent and turn it into a business empire takes real skill. In other circumstances or an earlier generation someone else would have figured out a way to exploit them and pocket all the money. They figured out how to develop a market for what they have to sell, monetize it, and keep the profits for themselves.
There’s an old fashioned way of thinking where Elon Musk is a genius and the Kardashians are trash. But they have similar success: they found something nobody else was doing and found a way to make lots of money from it. Whether or not you like the product isn’t relevant.