While I feel you described a real problem and I'd really like to see companies give it attention (you got my +50 claps) - It doesn't happen in a vacuum. Engineers moving between companies transfer knowledge with them. Rewarding new hotshots can be risky if they decide to leave (and my uess is younger engineers are more likely to). You should pay your engineers enough so that if they decide to accept other offers - you won't regret it and think "I could have paid them more and maybe they'd stay". I feel the more dominant problem is that engineers are expected to ask for a raise and not all of them do. especially not male engineers. You should have routine salary adjustments for all employees (which sadly most companies don't have). That alone should already make things much better.