Read the definitions of recall and precision. Interviews focus on precision at the expense of recall. That doesn’t mean interviews don’t evaluate competency. It’s just that not every competent candidate can pass.
> The fact that a service exists to make you better at interviews implies that interviews don't evaluate competency. If interviews evaluated competency
The only interpretation of this statement I can’t think of is “interviews do not measure competency.” That’s not true. They do, but the bias for high precision instead of high recall. That is, it’s better to pass on a competent person than to hire an incompetent one.
Regarding the guidelines, I’m not sure what you mean. One of the guidelines is to assume good faith, however.
