But this is also common in algorithmic interviews, correct? Like if I have a sheet that says bubble sort is the answer, and you provide merge sort then you are marked wrong.

The interesting thing about mcq is that their administration is completely standardised so it's more objective in pretty much every sense.

Maybe you prefer algorithmic interviews, that's fine. But I really don't understand how you can believe that they are less subjective than algorithmic interviews.

They avoid the bias of using different interviewers which is massive, even if the questions are standard.