Even a rooted phone will not help, since the monopolistic baseband processor will do it. The big ARM CPU is just for the users, the baseband is for control of the public masses and mass surveillance.
The surveillance problem is not black and white. A rooted phone may not help you if a state actor is after you, but it will help against companies that make money by building an invasive profile of who you are and what you do. Again how much a rooted phone helps in that depends on how many ties you want to cut with the digital-advertising ecosystem.
Here's a paper describing the privacy invasive and potentially harmful properties of pre-installed apps [1]. I specifically saved this paper in my files so I can have a comprehensive answer when people ask me why I go through the trouble of rooting my devices.
P.S. People who know more than me are saying that the baseband processor can be restricted with hardware practices such as IOMMU [2]. I don't really know how effective that can be.
The baseband processor isn't running Siri or Google Voice on my phone. Yes, if the state has a back door into the baseband processor there's not much I can do about it, but that's not the threat model that I'm avoiding by not using devices like the Echo or Google Home.
> that's not the threat model that I'm avoiding by not using devices like the Echo or Google Home.
100% this. IF a state intelligence agency is after my data they'll get it somehow (most likely just by asking). My concern is the rampant dragnet aggregation of personal data that I didn't expressly provide them by companies like Google and Facebook. I mean, Google having access to your emails that you store in Gmail? Kind of understandable. Google buying MasterCard transaction records to cross-reference against your web browsing data as tracked by any site using Google Analytics? No.
