The idea is if they fired 2,000 devs (for example), suddenly you have to compete with 2,000 people (who are all likely good devs) all immediately looking for a job.
This may not have been a problem in 2018, but it's definitely a problem in today's current environment with large amounts of bay area companies slowing their hiring.
If you look for a job before all this, you're in a much better position at least.
I wasn't around during the dot com era, but there were stories of devs ending up taking any job (programming or not) to make ends meet.
The market has slowed but I still think engineers from firms like Meta are not really facing a tough job market. It's just much harder now to get your foot in, to join startups, or to get hired from a less prestigious company.
The word "facing" is present tense, which is not the appropriate context for this scenario. Everyone will have trouble if Meta fires a bunch of engineers. People from Meta may have a little less trouble, and some companies will even open up new reqs to absorb some for cheaper. But there are a limited number of open positions out there. No real imagination or speculation is required here, since this has all happened many times before.
This may not have been a problem in 2018, but it's definitely a problem in today's current environment with large amounts of bay area companies slowing their hiring.
If you look for a job before all this, you're in a much better position at least.
I wasn't around during the dot com era, but there were stories of devs ending up taking any job (programming or not) to make ends meet.