I suspect that ultimately, most are just there to out-innovate would be upstarts that might, perhaps, take some of their pie. But this doesn't have to go on forever, there already is the precedent of Google not dying at all from utterly failing with their Facebook counter. And that's just one example. I believe that the "productivity crisis" is actually much deeper than it seems because so many parts are glossed over by zero sum games taking up some of the overcapacity.