My experience is that most of my time goes to writing cover letter (I should probably copy-paste, but instead I always reflect 'why I'm doing this' and write proper letter), never had to spend 30 minutes entering my details...

I feel the biggest blunder would be when applicant gets a take-home, spends some time on it and then there is no answer. Though I never experienced that myself. I never ghosted a candidate when I was on the other side of hiring table, but I was always finding it draining my energy to write the 'no' responses