> I don't care if someone can answer FizzBuzz .... All that can be learned.
Of course. But... sometimes it isn't. If a software engineer cannot do a question like FizzBuzz (and this does happen) then you can save a lot of time by cutting short the interview. If you're hiring SEs who cannot FizzBuzz, then I wish you the best of luck.
This isn't some leetcode or data structures trivia question that excellent candidates might fail. This is a test that I cannot imagine any good candidate failing.