I have seen these things closely. It kinda works out fine in big companies with large/slow IT departments. It takes ~3-6 months to figure out that person hired is not really up to task assigned. But still works in candidates favor because usually low level IT consultants are hired for 3/6 months + extension up to year or so. This means there is no point to proceed with firing that person as by then contract is about to be over.

Also I do not have latest info on this. The stories I have are from 2006-2016 period. So maybe with agile and all it is no longer possible.