Is this really a useful exercise? Why not present them with an actual problem that is relevant to your field and see how they approach it?
These are considered pretty basic stuff that every programmer should know..
The explanation I've heard is that good devs generally get hired after only a handful of interviews, whereas really bad devs are going to do a lot more interviews on average before they get hired, so you get a pretty skewed sampling even if there aren't that many really bad candidates around.
We are in a bubble, if we read programming blogs and think about programming in our free time, we are definitely not the kind that FizzBuzz exists to filter out. But from the perspective of companies, it makes sense if they really understood pointers or recursion or graph manipulation, because there are so many people lying on their resumes, not having sufficient analytical skills despite doing some resume driven cargo cult development etc.. And as an industry we don't really have an alternative to these algorithm interviews at scale, at the point we rely on non technical HR people to filter out resumes for us and they literally grep for framework/language experience.