I'd suggest virtually the opposite: a good way to be an outlier is to have reasonably broad knowledge plus being good at learning new stuff, such that when faced with a new problem you can quickly bring the right set of skills/technologies/whatever at it.
If you want to talk about it from a financial perspective, talk about the rate of return.
Can one developer do ten times the work any other developer does during a week? Probably not.
Can one developer have a rate of return such that they get ten times more valuable work done? Almost certainly.
So developer A delivers 3% improvement per year and developer B delivers 6% improvement per year. Across a career, if you start with 100 units, developer A delivers 245 units at the end, and developer B delivers 2008 units.
