Most of the pioneers responsible for making these companies what they are today departed over a decade ago.

I haven't heard a single convincing reason why these companies have so many employees, especially since none of them have accomplished anything in the same ball park as their predecessors.

When I hear "these are the best in the world" I laugh and walk away. There's better things to do than listen to idiots chest beat, attempting to justify their credentials. Real elites don't waste their time with the unimpressive and mediocre because they understand the real elite have achievements that speak for themselves.

Because "tech" workers are not required for the economy to be booming?

Because a booming economy is not what promotes hiring "tech" workers?

Because without ZIRP to allow VC to gamble on money-losing "startups", there is no place for these workers to "work"?

In the vast majority of cases these "jobs" lead nowhere, it is ultimately wasted effort when the money runs out, because the VC are making highly speculative bets. The majority of these bets will be wrong.

The money has run out, the high volume of speculative bets are no longer possible and the "workers" are not needed.

Because the economy is not booming.

The US economy is booming? What?