At one previous company we advertised a job and got five CVs total from it. Anyone who's done hiring knows that the quality of five randomly chosen applicants is not going to be high.

I'm 100% sure that the best person for the job wasn't the referral we ended up hiring, but the real best person was too busy sitting cross-legged on a mountaintop meditating on the meaning of pointers and writing all their code in haiku to send us an application.

You don't get to chose from all the people, you get to choose from the ones your hiring funnel brings in. Sometimes the market is tight and you can't find anyone good.