Being a 10X engineer at a small company I would say is both true and somewhat different at the same time. In the author's case it sounds like these were smaller

Being a 10X engineer at a small company I would say is both true and somewhat different at the same time. In the author's case it sounds like these were smaller companies? At every small company, there are people that are "super important", but similarly many people in different non-engineering roles are also "super important". My thinking at least on the 10X engineer concept was more like somebody who shows up at a larger company like Google or Apple and proceeds to make everybody there look like they are standing still while he/she produces far more / greater quality stuff than the average person there. In that case, if they left, sure the company would still keeping going, but you are outside of the 1-2 quantization question around where somebody is truly substantially more skilled than their peers. Big fish in a small pond vs. Big fish in a bigg-ish pond on the engineering side. It doesn't mean that you aren't necessarily a 10X engineer at a small company, but it just means the frame of reference is super unclear whether you are talking about somebody who is really hard to replace and super important to the company vs. somebody who truly is just knocking it out of the park left and right.