Apple is known for threatening companies that hire from them, and occasionally having secret agreements with other companies not to hire from each other.
People move from a company to a direct competitor all the time (i have a number of friends that went from working at aws to working on gcloud for example) and guess what, no one of those companies really went bankrupt due to this.
So really long story short: i think apple is being a sore loser at the employee retention game.