Super disagree with this theory, at least from my own perspective. I've been working for the last 25 years in various environments and I've never once even considered leaving due to anyone (high-performing or not) leaving. I think there's more factors to consider with something like this. If you're someone whos flakey, or just doesnt need your job, I would imagine you have a higher chance of leaving a job for a trivial reason. I'm like a oak tree, I don't quit jobs.