Comment by digianarchist

It's becoming obvious to me that my time is better spent learning to solve these riddles rather than actually becoming a better developer. I have a job search coming up at the end of the year and whilst I've managed to largely avoid companies that ask this type of question, I believe it's seriously constraining my career.

I can't speak for everyone but the whiteboard interview has prevented me from leaving jobs earlier, moving jobs more frequently and left me avoiding certain companies altogether.