Maybe there are other fields, like accounting, medical, etc. where certifications/exams really get to the heart of one's ability to perform?
I can only speak for the accounting field, but in my experience, that's not the case. The average CPA is likely to be better at any given tax or accounting task than the average non-CPA. But certification tends to weed out people who are not good test-takers, or who are lower income (can't afford prep courses), rather than people who lack the logic to resolve complicated problems.
After ~10 years of tax experience, I finally gave up and got my accounting hours and sat for the CPA exam. The classwork was interesting, and not completely without value, but didn't really make me better at my job. Same for the exam. But it was easier to become a CPA than to convince my clients that I wasn't one, and having it made me significantly more employable.
