most of them haven't even stopped hiring. pay close attention to the layoff announcements to see which ones also announce a hiring freeze - most of them haven't. and i've heard of a few people getting offers from companies that have done mass layoffs in recent months.
Also since everyone is “laying off their bottom 10%” and then rehiring from that pool thinking they’re hiring the top 10%. Sounds like musical chairs. There’s a old Joel Spolsky article on how everyone thinks they’re always hiring the global maximum
i'm sure there's some of this, but it doesn't seem like the broader trend.
if they were really laying off the bottom 10% there wouldn't be so many stories of managers complaining about their direct reports being laid off without any advance warning. it's hard to pick out low performers in any sort of sane way if you're not even asking managers who their low performers are.
