Yes there's a lot of money in retaining talent at any cost. That's what FANG companies are basically. The only problem being these firms are so good at making money they've sucked out a lot of the oxygen.
Most companies aren't as good at using their retained talent to make money.
Especially with remote work breaking down geographical moats at least within countries/regions, it's entirely possible that for most people salary-maximizing, they go with one of the big West Coast employers (or something like an HFT) if they can get in. And most other companies compete to hire everyone else.
Of course, hiring practices are sufficiently random in many cases that it's not really a matter of those firms skimming all the cream (and salary is only one factor that many go by anyway). But it is harder for other companies to salary match the likes of Google and Facebook.
Most companies aren't as good at using their retained talent to make money.