Earlier quoted context omitted.
Provisional hires (which often exist in theory but they're pretty much a formality in general) don't work for the most part. Lot of overhead for the company. And in many cases you're asking for the candidate to quit a job and possibly relocate on the possibility they'll get a new position assuming that they click in a short time interval.
So, accept the overhead as the cost of hiring the right people?
Yes, sometimes things just don't work out. But, if someone quits a job and maybe relocates, that's a big personal cost. It's just the way things work in some limited contexts (e.g. professional sports) but it's not and shouldn't be the norm.
I suppose you can give a huge sign-on bonus with no claw-back provision, but that's never going to happen in most cases.