I actually suspected that this was going on years ago, when I kept applying for jobs and never hearing anything back. After the first 100 or so jobs, I got demoralized and never got to the point where I wanted to try so hard again. It seemed like the effort was just going into this confusing black hole and nothing was coming back out. The definition of insanity is trying the same thing over and over again expecting different results, so eventually I concluded that most of the jobs out there aren't really available. The only job I ever applied for and got, was as an overnight stocker at Wal-Mart, and I didn't last a week in that position because it was too hard a job for me.
That whole experience of endless applications winding up in a black hole, and then the only job experience that wasn't like that leading to a deeply unpleasant job that I couldn't actually handle, just led me to be very discouraged from applying for jobs in general, and somewhat spin my wheels for the rest of my life.
The existence of "ghost jobs" does make me feel at least somewhat vindicated in my old complaints that "the jobs aren't out there, my resumes just go into a black hole." People would always say the idea of fake job postings created to waste people's time was a paranoid conspiracy theory on my part.
I guess it just goes to show that being intelligent doesn't always lead to success. People who had an irrational faith that the jobs were out there and the persistence to keep trying did better, whereas I correctly perceived very quickly, after a few hundred applications that most of the jobs were fake and that effort was being wasted on my part, but that awareness was actually detrimental to my own well-being.