As Tears For Fears noted, "Everybody Wants to Rule the World." Ordinary people worship Billionaires because billionaires get to live in ways the rest of us only dream about. They have the power to indulge any dream or fantasy, they are only loosely constrained by laws, and they are usually famous too. Whatever your personal opinion about those facts, those are the facts, and pretty much everyone has entertained fantasies about having such a life for themselves. Billionaires are the embodiment of poor people's fantasies -- and we're all poor in comparison. I wouldn't say that ordinary people worship billionaires. Instead, they worship the false image of a billionaire's life, like worshiping the Kardashians, which ordinary people do in large numbers.
You overlook that some billionaires are also responsible for creating useful products. I greatly admire Elon Musk, a billionaire, not because he has billions but because he's single-handedly advanced entire industries by decades. I admire achievement, and a I appreciate the collective fruits of his success. I think the work Bill Gates has done with his foundation is amazing and admirable. Ordinary people like me need not be financially desperate to see good in the lives of billionaires.