In such a case, let's imagine a programmer in a department of 100 people. I take that case because to me Impostor syndrome relates to a peer group that one is actively engaged with - not to an abstraction.
Anyway, in this case, he believes that 98 people in the office are no good. 1 is amazingly good. He is both better than the 98 but much much worse than the 1. To my mind that is not impostor syndrome.
Perhaps I don't really understand the term.
Wikipedia does a better job: https://en.wikipedia.org/wiki/Impostor_syndrome
Not at all: you can be painfully aware that 90% or even 99% of your peers are not that good and yet you are still light years away from being in the top 0.0001%. It's the same type of awareness.
Compare it with income only for the sake of having a numerical benchmark. With a salary of 32k$/year you are in the world top 1% yet you might feel you should be earning 100x that.