But do you really think they accidentally over-hired to the tune of tens of thousands of individuals? Across these companies the numbers are close to 100,000 people. Maybe much more.

That means that a large number of high ranking people in these companies projected they would need these people in the coming years, and then some.

I think it may be darker than that, and the overhiring was a tentative measure to build up a charge, like electrons in a capacitor, to release a shock to the market that would achieve two aims:

    1) drive salaries down through fear and contest

    2) reduce the bargaining power of employees (software engineers were starting to look to unionizing in the past 5 years especially and that has gone deathly quiet even though working conditions have worsened and demands have increased on 'ICs')

Any objection as to whether these companies executive teams were collaborating on such aims should be seen as very empty by now, given we know they are all deeply circularly invested in each other and thus are bound to each other's success or failure.