People repeating that stuff are true believers. The reality is that the politics of companies is complex.

I can think of people I know is big tech companies who were nearly fired. One guy ended up serving out a purgatory sentence as a CE because his boss got whacked. A year later, he’s an SVP when a friend of the old boss took over.

Ditto the opposite. A friend in a bank collects low performers purposefully to protect his core teams. He dutifully offers some cannon fodder up when the company demands tribute to the volcano gods.

There are genuine low performers, however, based on my personal experience, they generally only constitute 25% of the people laid off for low performance. If management has overinflated expectations of your project, you will be a "low performer". If you happen to do badly on a project with high visibility to senior management, you will be perceived to be a low performer too, even if your delivery on other projects was brilliant. If your last project failed, often because of external factors, you will be deemed to be a low performer.