That's the problem. Google can regularly update Chrome without updating the OS. Apple can't because it's a system app.
> Apple have always put the end Users Experience before Developers, so it's primarily focused on maintaining a fast, fluid browsing experience on iOS
Not really. They actually started backtracking on most of those. They even allow third party keyboards now, most of which are slower and harder to use than the stock iOS keyboard. Considering keyboard is a more integral part of the OS, it seems weird they still do not allow third party browsers.