Realistically, they would be very uncommon, and odds are that your small company has 0 of them. Of the developers I know that are actual superstars when compared to average developers, they have zero problem displaying their value and make upwards of 7 figures. All of them are aged 40+ too.
So, yeah, I don't have a problem with the concept. I just think it gets misapplied.
Who labelled them? The self-labelled are often crappy.
The last superstar I worked with seemed like a Cro-Magnon developer. He used outdated tech, didn't understand many modern dev techniques. However he was extremely productive (he was very very good at concentrating on necessary outcomes and ignoring make work). His value was _far_ more than 10x the average developer. He certainly didn't seem to be valuable. Despite his serious faults he produced gold. He was wildly undervalued by other developers.
Keep your eyes open - some superstars are invisible. This especially holds in other soft areas like marketing.
That’s who I imagined.