Earlier quoted context omitted.
How come the argument "you can just buy an android phone" doesn't apply to iOS users in the same way "you can just sideload an APK" does to Google play store users? This isn't a rhetorical question, I'm genuinely curious about how people think of these distinctions.
You don't have to "jailbreak" your Android because it wasnt in jail to begin with. Sideloading works straight out of the box.
Given that the application store can be changed to blacklist a certain app, it is not unlikely that the next step is similar changes to the apk installer.
It should also be noted that there are no guarantees that signature checking is optional in all future builds of Android. While there are differences between the iPhone and Android business models, they should also not be overstated. My personal guess is that they will drift closer over time rather than farther apart.