If you are working with a service that promises you applicants for that hard-to-fill position, well, the end game is money and a promise delivered. They can't really help the quality of applicants, after all, since they don't discriminate and aren't actually doing the hiring.
I'm guess the "fake" resumes are just people with really, really bad resumes. Which is easy to do on linkedin (I don't know about indeed), because you just click one button to submit whatever you've chosen to fill out.
right now alot of people are looking for work. the less people that apply, the better your chances are of getting the job. so if you see that only 3 people have applied, then you apply and flood indeed so it shows over 100 people applied, chances are noone else will apply. your odds of getting the job have gone up.