There's two parts to being successful at a job: successfully accomplishing the work that fits into your role, and successfully messaging to your bosses that you're doing a good job.
So when executives lay people off, it tends to catch people who are bad at that second task (the messaging/perception side), which may or may not include people who are good at the first task (actually doing good shit for the company).
That's why mass layoffs are damaging, and should be avoided if possible.