Is this something to be worried about? Yes. But it is mostly too late to doing anything. The move to the browser has been happening for years. As an example,

Is this something to be worried about? Yes. But it is mostly too late to doing anything. The move to the browser has been happening for years. As an example, look at ChromesOS - a cloud operating system (OS) that tracks and records all your activity the moment you sign in. A Google account is required to use the full functionality of the OS. It is used by millions of schoolkids with all the privacy implications that entails. Somehow, Google's promise to never build profiles of their school users is enough to placate developers. In fact, developers are more likely to defend Google rather than question or scrutinise the privacy implications of using a cloud OS. Google must be gleeful they've captured a whole generation of US kids to use Google services through the ubiquity of ChromeOS in US schools. And without any dissenting views from developers on the matter either.