Investment management is a classic example of this. CFA has a low pass rate (it isn't that hard really, tens of thousands of people do the exam in India and China so that impacts the pass rate), most people do it but, ofc, the really useful knowledge can't be tested...picking a stock isn't like passing a exam. And worse, you get lots of people who pass the exam, acquire false sense of confidence, and then make mistakes (or don't ever move beyond the "parrot" level of intelligence).

I think maths is another one, as conventionally taught. I hated maths at school because it was largely sitting down in a room, doing the same thing over and over again like a computer...quite reasonably, I asked myself whether this was a productive use of my time. As an adult, I have taught myself everything again, it was far more enjoyable and useful because I actually took the time to understand the concepts (and no, none of the stuff I did at school was useful, it was just mindless computation).

I don't necessarily think exams are a bad idea but they don't produce knowledge, experience, or real expertise. They are often misused (as is certification, I knew a guy who worked as a fund manager and was a senior member of the CFA for ethics and standards...he stole from employees regularly).