You're right... for now. We're seeing incredible concentration of wealth. Eventually they will become lazy and overly bureaucratic. Google, Apple, and Facebook in particular made their mark by dismissing customer service and by not addressing customer complaints, creating a culture of the "one true way". That culture + monopoly status will create (and is creating) a toxic miasma.
Apple has fairly good service if you show up at one of their stores with a broken device. Google and Facebook will also sometimes provide good service for actual paying customers, just not for users.
Also, the big technology corps are fighting their lack of internal innovation by buying smaller competitors. The executives are well aware of company lifecycle theory.
