It's pretty simple: "it's my phone, I do what I want with it, just like my house or car".
Which includes "go to any website and run any app I can download from it, regardless of whether it's illegal or against any rules or against the interests of the phone maker" and "change any aspect of functionality that I don't like (e.g. apps being able to show ads) and that I can find out on the web how to change".
It doesn't include "Google or Apple make rules about what I can do with my phone that I can't override".
Which includes "go to any website and run any app I can download from it, regardless of whether it's illegal or against any rules or against the interests of the phone maker" and "change any aspect of functionality that I don't like (e.g. apps being able to show ads) and that I can find out on the web how to change".
It doesn't include "Google or Apple make rules about what I can do with my phone that I can't override".