Look at it from the candidates point of view. You have a set of questions or a task you want us to take the time to complete. We do not have the option to ask you questions and see if it is a good fit. That is one reason why we see it as unfair.
Now I understand that you may have hundreds of applications, 24 hours in a day, and a deadline. I don’t have a better solution for you because I’ve never hired anyone, sorry. I feel for you but many people hate one way interviews.