Employers have some insight, perhaps not perfect, into which existing employees are good but for some reason there's a pathological need to treat existing employees as undesirables, leading to a constant need for hiring new employees, whose abilities are unknown. Stop trying to save a couple percent on compensation by letting employees leave when they want more of their true value recognized financially. Stop expecting employees to adjust to constantly changing business fads on their own time and dime. Stop letting toxic management run off employees for non-business reasons.

Or continue to be in one of the most labor rich markets of all times while starving to death from not being able to be nourished by any of it. Make use of the employees you know instead of having an extreme preference for the potential employees who are a complete mystery.

It has always been hard to tell who will be good at a job based on a CV and a bunch of short tests. AI has just disrupted the stupid proxies created by HR, because now everyone can fake being a good CV writer or doing leetcode.