I never saw productivity as a function of raw speed of churning out code. Some of the most productive engineers I know are about average at coding. They just seem to know how to perceive which areas of work would have the most impact, and focus on them. They are also generally experienced enough to avoid pitfalls, both technical and organizational.
The few engineers I know who approach 10x productivity have done so by building tooling that helps all the other engineers do their jobs easier.
Sometimes there are just no magic solutions.