You can implement binary search recursively, which doesn’t care about the stack just the final iteration. I don’t see where the stack unwinding is necessarily f

You can implement binary search recursively, which doesn’t care about the stack just the final iteration. I don’t see where the stack unwinding is necessarily for “call the same function inside itself unless you’re done” except in cases where the stack is used to compute a final answer that’s based on the prior iterations. Maybe it’s fair to say those would best be implemented iteratively, but it’s unnecessary that they be.