How do you sort an infinite stream?
If a list is sorted, then you'd be able to return the largest value. Since that is impossible the correct answer is that it's impossible.
the purpose of the interview is to filter out people that do not know the answer or have pre-learned something and don't fully understand its applications. When you are in a dialog it is a very different dynamic,
people that would not ask a question because it is already posted on leetcode are the problem the OP complains about
This answer would make you fail the interview :-)
Hope I never pass your interview!
This sort of thing is sadly common in interviews, where the interviewer some arbitrary answer in mind and expects you to read his mind, which is possible only some of the time.
By definition you can't sort an infinite list. You've conveniently turned the question, in your mind, into something like "how do you efficiently maintain an ordered list of incoming items?"