Also, if the interview process is a whole day, you're excluding candidates who already have a job.

Demanding applicants to spend a lot of time only works on recent grads, or unemployed and desperate.

I'm starting to use it as an anti-filter. If a job prospect demands me to invest time before an interview, I just pass.

Who are you that I should waste 5-10 hours on your interview project, before I even meet you?