Google figured out the frobenius whatever eigen vector of the web graph a couple decades ago and have been selling ads ever since

Microsoft and Oracle mostly makes enterprise SaaS, pushing pixels

Yeah, they do cool stuff... resting on the chip technology developed for missile targeting by the military. Boeing, Lockheed, Northrop

The fraction of advanced research done at the big tech companies is very small overall. Nvidia and Apple do more interesting things, but by the nature of being stuff that has to be built in large volumes, it's less bleeding edge than what happens in aerospace & defense.