If the author's premise is correct, there should be a lot of money to be made in retaining talent. Some of that should filter down to more than 3% raises.
So if you believe in humans as rational economic actors, there is "$20 bills lying on the street" if you build a tech company that hires, increases comp, and retains, rather than the current model of hire, churn, poach.
I realize that double-digit raises at the same company is a big culture shift, but I've seen it done. If everyone benefits, why wouldn't it happen?