A leaderboard updates as new applicants are screened, so the order can change during the day as more candidates complete a CV review or screening interview. Each row usually shows the candidate's overall score alongside the scores for individual criteria, so a recruiter can see why one person sits above another. Filters let teams view, for example, only candidates who have finished every stage.
When hundreds of people apply, a ranked view lets recruiters spend their first hour on the most relevant applicants rather than working through applications in date order. A ranking is a starting point, not a decision. Good practice is to check the evidence behind top scores, look below the top few rows for strong candidates the criteria may have missed, and keep a person responsible for every outcome.