Arguably from what I've seen it is TOO random or non-performance based.
Some combination of personal dislike and unfamiliarity.
The people making the cuts are not line managers and are sometimes given very short amount of time to make their cut list. So "oh I know that person" stays vs "I have no idea what they do / they asked me a pointed question in a meeting once" goes.
I've been laid off twice, neither time has been performance based.
once i was on a team of 2 ICs and a Manager - only the manager stayed - the company is now about to fold. Other time i was let go as part of the entire US arm
Yes, most layoffs I've seen in my career are of the "mass layoff" variety, and these are generally far from being performance based.
There's just too many people, the decision making is too quick, at too high a level.. and more driven by cost / future strategy (so which teams to cut deeper).
Some combination of personal dislike and unfamiliarity.
The people making the cuts are not line managers and are sometimes given very short amount of time to make their cut list. So "oh I know that person" stays vs "I have no idea what they do / they asked me a pointed question in a meeting once" goes.