I think that ends up pretty nuanced. A cheap $50 Android will receive security updates for one year if you're lucky. So now you have a choice between buying a new cheap phone yearly, forgoing security, or being technically savvy enough to put a 3rd party OS on your phone. With regard to privacy, smart phones really don't have options for privacy unless you go with a 3rd party OS. And, if you do so, you might not even be able to run the various apps which the various businesses require. I just don't see this as a valid alternative.