Nobody earns a billion dollars through honest work. You don't become a celebrity billionaire on your own. Creating and maintaining celebrity takes a large team of workers who sees none of the profits created by the celebrity.
Those profits are most often created by being able to demand far greater prices for branded merchandise than the cost of labour and materials, justified solely by the brand and image of the celebrity. This allows them to extract a form of monopoly rent by creating an artificial scarcity in the market.
Celebrity billionaires might not be the most consciously evil billionaires but they are exploitative and parasitic, just like any other kind of billionaire.