iCab for iOS is very impressive, but it's still a wrapper for Safari and Safari is only ever updated when iOS is. The main problem with this is security. Apple have a poor record of fixing exploits in their software and the Safari team don't seem to care much about strengthening security. For example, while both Mozilla and Google have
assisted Cryptocat in ensuring it's secure on their browsers, the Safari team hasn't responded to the Cryptocat team or even so much as approved the Cryptocat extension to their library.
On iOS, not only are all browsers forced to use this engine, but the engine is only updated when the OS is. So if you're on a device Apple is no longer updating? Too bad, no security fixes for you anymore. Ever. On Android, even if you're on a device which isn't getting OS updates and you don't want to install custom ROMs, you can still update the browser independent of the OS.
On a more general note, this also means that all developers can do is stick features on top of Safari rather than innovate on the actual browsing engine.
Furthermore, Android goes even further on the security front here because you can actually install
NoScript and
AdBlock Plus on Firefox for Android. Although iCab has a very basic ad blocker, it doesn't have these kinds of tools and the ability to add them in the future is limited by Apple. The kind of advanced protection NoScript offers will never be available in the App Store.
Basically, Apple's insistance that developers and users shouldn't be able to fully access the system is a major downfall. All of this stuff I've mentioned can be done on Android without any rooting BTW.
P.S. And Apple will still never approve a FetLife app
🙁