In an ideal capitalistic world billionaires are people that provide most value to society, yes. In the real world it’s questionable to say the least because they usually do not do fair win-win business, they do cutthroat “I’m gonna abuse my position to the absolute limit, what are you gonna do about it, you have no other choice” business. People that don’t do that don’t end up billionaires because they can’t compete with those that do.
The definition of „value“ in capitalism is already contentious, so even in idealized capitalism billionaires can provide „value“ that does not align with the „value“ of most of the people.