The OP ignores the fact that at most decent tech companies, a TON of time is spent on annual or semi-annual reviews to determine raises and bonus comp for better performing employees. The exact reason this is done is to ensure they're being compensated fairly and don't go off shopping for offers.
It's not true that management has the goal of minimizing comp for employees. Management tries to minimize _total compensation expenses_, which includes the costs associated with replacing an employee (and those costs can equal a full YEAR of comp in most cases.) Not to mention the disruption to projects that occurs when a key team member departs.
Really smart tech companies take a step farther: if you're in good standing when you leave, they have a special process for hiring you back if you decide you want to come back later. It's smart: they expect that lots of the best employees will want to try their hand at a startup or smaller venture at some point, but they don't burn the bridge with someone they know is a good team member.
It's not true that management has the goal of minimizing comp for employees. Management tries to minimize _total compensation expenses_, which includes the costs associated with replacing an employee (and those costs can equal a full YEAR of comp in most cases.) Not to mention the disruption to projects that occurs when a key team member departs.
Really smart tech companies take a step farther: if you're in good standing when you leave, they have a special process for hiring you back if you decide you want to come back later. It's smart: they expect that lots of the best employees will want to try their hand at a startup or smaller venture at some point, but they don't burn the bridge with someone they know is a good team member.