You don’t need direct file access and prevents a third party device from potentially transferring malware to it.

What malware lol. ClickForFreeMoney.apk? Even then, the applications are sandboxed pretty well. Even if you install “malware” it won’t be able to do much unless you also grant it permissions to access personal data.

As for trusting ad blockers, unless you are downloading and building each update yourself. You are still susceptible to a supply chain attack or bad actor even by using open source.

Most adblockers (all the good ones) don’t require frequent updates. They frequently update filter lists, which don’t execute any code and therefore can’t do anything malicious. And what you said applies to every application ever. Anyone can have their credentials stolen and used to publish a modified application.

I’m just trying to make the argument that iPhone isn’t inferior to android and vice versa

I don’t disagree, Androids and iPhones are pretty much at feature and quality parity nowadays. But it sounds like you’re starting from a conclusion and working backwards, which is not a good way to think.