I agree. My day job is working on code that isn't this level of critical, but also has the characteristic of being low level, both closer to the metal than typical backend code and also called by so much frontend and backend code that if there was such a thing as "even backend-ier code" this would be a good example. If you miss a nuance, a horde of angry developers will show up at your desk the moment the build deploys, and if you don't fix it fast, that turns into a horde of angry customers.

With code that far down in the inner loops of mission critical code, the dominant time cost isn't really writing or even understanding the code, it's ramping up on the nuances of the scenarios you serve, checking the direct effects of your changes, and then checking the second order and third order effects of your changes.

When your code is so far down that every change you make has third order effects, it's a lot easier to maintain code that is meticulously commented and written for maximum thoroughness explicitly baked into the file in front of you, because you're much more likely to miss the nuances if you just finished piecing together ten different files to figure out how the happy path works.