Because, given you aren't filing for PERM these days for someone that you have not already hired, someone off the street is going to be straight out worse than your current employee.

PERM ade sense in a theoretical world without H1s or F1s, where you are filing PERM for someone off the street. But that almost never happens outside of cases where yes, you coud put the ad in the front page NYT and you'd still hire the candidate. And thus eitehr way you slice it, looking at the resumes of your ghost ad is a waste of time either way.

And if one really wanted to go back to that kind of green card process, it has to be very fast anyway, instead of being as slow as it is. Otherwise it becomes useless regardless.

Yet the law says they have to conduct a good-faith effort to find someone in America who already has authorisation to work (whether a citizen, green card, refugee, asylee, TPS, etc.) who is equally or more qualified.

If it's a given that "nobody else will be more qualified", then they aren't making a good-faith effort, are they.