I guarantee that companies (at least large companies) do reconcile hiring decisions with performance review data. Google, at least, has entire teams of analysts

I guarantee that companies (at least large companies) do reconcile hiring decisions with performance review data. Google, at least, has entire teams of analysts focused on exactly this sort of analysis. Fundamentally, hiring is simply not an easy problem. There's a small cohort of candidates who can be reasonably confident will perform well in a job (mostly people who have performed a similar job at a competitor) that everyone competes over and a marge larger group of candidates whose possible performance is very hard to judge.