Earlier quoted context omitted.
Can john carmack build 10 crud apps in a week?
Pretty sure he could if he got to practice writing crud apps for a month beforehand and the apps were no more complicated than what a mediocre engineer can write in a week.
If you instead hire 10 engineers to write 1 app each, you often end up with 10 apps using 8 different frameworks in 3 different languages. And then you will need 10 engineers to maintain them.