I feel like people are confusing the meaning of "taken over" because it means both "outnumbers" and "controls".

Electronic messages outnumber paper letters, but humans still control both.

Well, I mean it in the sense that, if you turned off all of the microprocessors, what would still function? Almost nothing. Ergo everything that would die is "taken over" fully by automation, in a way that should concern people but not terrify them.