> you start to realize _why_ there's a stack, rather than just a single technology to rule them all
Architecturally, there are other cases besides message queues where there's no reason for introducing another layer in the stack, once you have a database, other than just because SQL isn't anybody's favorite programming language. And that's the real reason there's a stack.
The rationalization given in this comment for the layoffs is obviously false. Google had ways of getting rid of underperformers without massive layoffs that they have been using for many years. Google has ways of getting rid of projects that do not involve layoffs.