You could argue that without the iPhone smartphones as a market might not have taken off in the way they did (I don't have a good enough knowledge of the history to judge) but I don't think it's fair or accurate to say that Android was just a reaction.
Android in 2003 was created to rival with Symbian and BlackBerry but was struggling to be funded
At Google it became the Linux based OS that we know today, but Google was still marketing it for the mobile devices of the time that were nothing like modern smartphones
The real switch happened when Apple released iPhone + AppStore integration that showed the potential of the smartphone devices bundled with a closed ecosystem of apps
Google and Facebook were already in the market of tracking users habits, but it's smartphones that unlocked their true power and enabled them to subvert the open web to their advantage
Apple has never really been interested in the web, they wanted apps for their smartphones and Google and social networks apps, especially Facebook, were a major selling point that drove their enormous success in the mobile market.
Apple made something that Facebook and Google only dreamt of: they put a spying device in people's pockets
Android was only a reaction to their success