Unicorns aren't who benefit from such a structure. The marginal quality hire is - the person who would be good enough if they were offered the job, but who, for one reason or another, are deemed too risky to hire at current market prices.

One only has to browse a place like r/cscareerquestions to get a sense that many people, early career especially, find themselves in this situation - stuck perhaps in the dreaded "can't get hired without experience, can't get experience without getting hired" catch 22.