But it all comes down to how an interviewer is evaluating and dealing the candidate isn't it? Coming up with reasonably quick solutions might not be the criter

But it all comes down to how an interviewer is evaluating and dealing the candidate isn't it? Coming up with reasonably quick solutions might not be the criteria for some interviewers, but this is just a tool to make the process simple. How one conducts the interview is not something we can control.