Google controls 90% of the browser market, and 70% of the mobile OS market. They can force anything they want down the throats of billions of people, the vast majority of which aren't even aware that there are alternatives. And even those that are aware are in many cases unable to switch, as for example most phones will only run their manufacturer's version of Android, from which Google features usually cannot be completely removed.

This isn't even remotely comparable to the AltaVista situation. Google has a planet-scale stranglehold on how half the world's population accesses information. This arguably makes Google more powerful than most nation states. I can guarantee they won't be dislodged by some search startup with a cool idea.