Reposting as a non AC.
There are some reasons for the unrealistic job descriptions, they are a lure, and are generally loosely associated with the role (ie: 80%). We're hoping for a purple unicorn, but know that they don't exist. But would settle for a winged horse, a unicorn, a purple horse or more realistically a good horse. But occasionally one of the unrealistic mix of experience does come through.
It has been almost a decade since I last went through an applicant list for a particular role.
What happens most times now is an application is added to an applicant tracking system. This parses the resume (from word, pdf or text) and creates a database of candidates matching keywords. This meatgrinder approach means that when I am looking to fill a position, I don't actually look for applications - I might - or the HR might quickly review the actual applications. What I do is search and screen. Search for a set of keywords, and from that list look for obvious issues (applicants to every job, rejected candidates, age of resume, etc). And then the HR recruiter will screen down from there.
I'll typically get 20 or so resumes to review. The recruiter may review 100 to 200 resumes. There pool of candidates may be 2000 to 3000 of which only a small portion are for my position.
This is part of the reason that resumes have gone from minimalistic to more fully descriptive with keywords sprinkled throughout them.