Have you considered that FizzBuzz is a warmup question to see if you're worthy of a properly challenging question?
The interviewer has multiple responsibilities, one of them is candidate experience. If I start with the "challenging" question and the candidate isn't ready, then I learn nothing other than they can't do it and the candidate suffers, completely lost.
But, if I start with a middle-to-low bar question, then I can always get data and easily extend or follow-up the question with something more challenging appropriate to your skill & experience.