This might not be truly universal, but by and large coding interviews can be and has been made more or less a standardized test, whiteboard or online collab (e.

This might not be truly universal, but by and large coding interviews can be and has been made more or less a standardized test, whiteboard or online collab (e.g. HackerRank, CoderPad, ...) alike. Like any standardized test, you can practice to become more or less consistent. It's true that some interviewers might hand out whacky and/or ill-defined problems, but my experience on both sides of the interview indicates that the average difficulty of problems has converged onto what is now known as "LeetCode Medium". The problem will be random, but the difficulty won't. Why this benefits interviewers is left as an exercise for the reader.