It tells me a lot about how a candidate will work within a team if they're capable to actually bounce ideas back and forth and explain their thinking, and I've often preferred someone who doesn't get as far but who can show me better communications skills and who seems eager to learn.
- Is the interviewer looking for syntactically correct code, or general algorithmic skills?
- For a warmup, is the interviewer looking for a basic solution, or an optimal solution?
- For architecture walkthroughs, what level of detail is expected?
The extra pressure is definitely unnecessary.
[0] https://hiringfor.tech/2020/03/02/are-you-asking-candidates-...
I like to ask open-ended questions. "I am trying to solve X problem, how should-I do it?". That reduces the rote bias and also checks if the candidate can communicate.
However, one guy told me he now uses the question as his actual interview question because he thinks the way people suffer thru a seemingly impossible problem reveals how good of an engineer they are :D