If you hire 30k people that you shouldn't have hired, when you let 30k people go it will probably not be the exact group of 30k that you hired, some will be folks that have been there for a while.
And to anyone complaining I just say: "welcome to the tech industry?". Layoffs are a very normal part of our industry and it happens all the time. And as former Google engineers, I'm sure none of those laid off will have trouble finding work again.