A corporate job typically gets 250 applications. Of these applicants, about 2% to 6% are called in for an interview. Of course, the offer is made to just one. This means that there are about 249 candidates who get rejected each time you post an ad.
Now, no HR professional wants to break the bad news of rejection to the candidates. But informing them about their application status is important as it helps them to track it to closure.
More information: https://blog.recruitee.com/job-rejection-email/