This really depends on the percentage of the workforce your laying off. A small %2-%6 one is really getting rid of people you don't want, but it's too much of a pain in the ass to do the entire PIP & political process to do so, or they're toxic / unproductive but well positioned that firing them is hard. A streamlined 'just pick people' layoff process helps with all of those issues. The bottom %5 percentile people that get dropped in a %5 lay off were already near the chopping block. While larger %10-%50 layoffs are really economically motivated.

The thing is although, you can't do %5 layoffs when your doing well, or the economy is doing well, so you use such times as now as an opportunity to do so. You'll know the layoffs are more economically motivated when there are multiple waves or they become larger in percentage of employees.

Like why did the google layoff %6? I definitely think it was a trim the fat operation, and the opportunity to get rid of some well positioned, unproductive long term rest-and-vesters, which is why a bunch of very long tenure people got laid off at google now.