I think we need to put the myth of the 10x developer to bed. 99% of the time, the 10x guy is just someone who solved the same or similar problem at his or her last job and are simply exercising their experience. Sure there are outliers, but that's the same in every field - whereas in programming 50% of people believe that they're the 10x guy and that all their cow-orkers are slothful idiots.
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.
Some tough problems that took other skilled developers months they could solve in a couple of days and they could consistently do it across the tech and domain sphere.
I think the issue is people claim to be 10x, if you're claiming to be 10x then most likely you are not, the 10xers I've met have all been very humble.