Wait, what?
That's not an argument. Desktop browsers have features and add-ons for the privacy conscious right now. You can block trackers, third party cookies, JavaScript execution and anything you need. Personally I feel much, much safer loading a website than when executing a binary on my computer or phone.
You can block any elements on any website from loading, but you can't inspect application binaries and block specific elements from it — only requests to certain IPs or domains, if you had root access that is.
Can you block Facebook's in-app advertising on your iPhone? You can't and even more so, the app insists on opening all URLs in its own dumbed down view instead of Safari, which means they track those visits and their duration as well, probably without content blocking active, because AFAIK it doesn't work in web views.
Well I can block Facebook's ads and tracking in my Firefox for Android, since it supports extensions and it probably works using iOS Safari's content blockers as well.