I think this is a key observation. I of course cannot speak for every case, but in the couple of layoff rounds I've been witness to, for unrelated companies, layoffs are done without relation to individual skills or contribution.
Or rather: they may start with low performers, but these aren't enough, and then the next people that get axed are good performers (sometimes brilliant in my experience) for areas that the execs deemed not important enough for the company. Key words "not important enough", not unimportant. They are also done by people who don't know the team or its members, resulting in firing people who were later found to be essential, and their manager cannot speak for them because the manager was also laid off.
In the end, remember this when judging your "loyalty" to a company.