I have never sent an interviewee to the whiteboard.
Algorithms are mostly wrapped in existing classes and hardly anyone not at google works at that level ever. I haven’t worked with a linked list in 20 years and I’ve only worked in binary trees in interviews.
I ask questions about approaches to problem solving. The eager conformists get a thumb down; the ones who disagree and can defend are candidates.
Whiteboard interviews are tests of working under scrutiny, not coding ability.