Not in my experience. The most recent one was a developer who joined every standup from the ski slopes, when asked to work on a particular task responded with "I'd rather not work on that, can you give me something easier?", and failed to ever actually work on anything. We still had to go through the whole drawn out process of working on a performance improvement plan with them. They simply didn't care.

I don't dispute the underperfomers are the typical case. But I've seen plenty of glaring exceptions. The point is: things aren't always what they seem. And we can't automatically assume that the people who make these decisions are making the right decisions, or even know what's happening under their noses.

BTW if they put the guy on PIP then that basically means they were in the process of firing him already. So if they called it a "layoff" that was for cosmetic purposes.