Unfortunately I used to think this was the main purpose of the interview as well, but have been proven wrong time and time again.
The only thing that matters in most places is getting to the optimal solution quickly. It doesn't matter if you explain your thought process or ask clarifying questions, just get to the solution and answer the time and space complexity correctly and you pass.
Like others have said I think this is a symptom of the sheer number of people applying and needing to go through the process, there is no time for nuance or evaluating people on if you would actually like to work with them or not.
The only thing that matters in most places is getting to the optimal solution quickly. It doesn't matter if you explain your thought process or ask clarifying questions, just get to the solution and answer the time and space complexity correctly and you pass.
Like others have said I think this is a symptom of the sheer number of people applying and needing to go through the process, there is no time for nuance or evaluating people on if you would actually like to work with them or not.