You and a bunch of others in the thread are starting from the presumption that these people were very well compensated. But we don't have to make _only_ assumptions, you can look up some perhaps stale and perhaps biased self-reported numbers. The most convenient of these to access for recruiters at twitter (who seem to be the ones impacted) guess a median compensation of 137K, with around 94k of that as base. I think that base is just about at median income for SF for a single earner (though of course they could live elsewhere).
Other people in this thread are talking about what I understand to be hypothetical engineers with 400k compensation, and it sounds like that doesn't describe this situation.
https://www.glassdoor.com/Salary/Twitter-Recruiter-Salaries-... https://sfmohcd.org/sites/default/files/Documents/MOH/BMR%20...