FizzBuzz isn't a programming challenge for interviews anymore, that was like ten years ago. Now its more like a data structures and algorithms exam.
Real tech interviews have always been about understanding and applying data structures and algorithms, with some emphasis on problem solving with those tools.
A really long time ago, there used to be questions that were more like "do you know some very common C/hacker idioms", like write a one line strlen or reverse a linked list in place. I used to get asked stuff like that in the late 90s.
(There were also the brainteaser style things, like how many golf balls fit in a 747, but those were often for non-programming roles where people were looking for your ability to problem solve in a vacuum with little information. Those were rarely aimed at engineers, but at engineer adjacent non-technical roles.)