Here is the thing though. Solving "FizzBuzz" is trivial if you happen to know how to do it. Same with "Pascal's Triangle" or many LeetCode style interview questions.
Solving either, particularly the latter when you don't "know" the test and are under pressure is not trivial. I have been in interviews for Ph.D. candidates who when asked simple questions like "Why do you want a Ph.D?" suddenly can't even remember how to speak English let alone explain why they want the advanced degree.
FizzBuzz is kind of a trap. If you don't know it, it seems like it would be easy to try nested if statements as candidates want to write efficient code and can fall into the trap of not wanting to repeat a test for 3 or they try a test for 3 then 5 then 15 before realizing that the easiest solution is three properly ordered if statements and that there is no "elegant" way to solve this trivial problem.
In fact, i work every day with data scientists who write perfect classification code and generate complex statistical models who would likely struggle to write FizzBuzz on the whiteboard in front of the entire team.
I hate interview questions like these and struggle to connect them to performance. If one must test then give a small project (something that might take me 30 mins to an hour) and ask the candidate to complete it at their own pace and publish their work in progress to a git repo. Can they solve the problem (even if they used google and/or an LLM)? Are their commits in meaningful units of work? Can I read their code in a review? Did they ask for proper clarification when uncertain? Do they have tests?
I find this much more salient than FizzBuzz.