The problem is, as I noted, spending $100 to post a completely bogus job 100 times is basically nothing to even a medium-sized company.
The asymmetry in power & wealth means that if you want the $1 spent by a job-seeker to even come close to the guarantees you describe, you'll probably need to make the company pay $100 per posting or more. And that would effectively require some pretty widespread and strictly-enforced regulation/legislation.
If you're going to have to get that just for this middleman solution, why not go all the way and have the regulation mandate that any job that a company posts has to be real, with full intent to hire, and every single applicant must get a timely, non-canned response?
The issue is thst we both know those won't happen. Even if it's just scam shops that abuse it and everyone else plays the honor code. Rotten apples and all that.
A) it is an actual job, with intent to hire now B) I will get an actual response, from a human, within a few days
Then $100 is completely worth the time saved vs applying to ghost jobs.