It's frustrating, but there isn't.
Most users don't stray from the bundled defaults, even on desktop, so there's little incentive to., and Apple's current mindset is far removed from the Think Different days, even if that was only a marketing slogan.
By allowing browser alternatives, Apple keeps clear of regulators, but that doesn't mean it makes it easy to stray from Safari, even for users who do wish to use something different. I doubt the EU would take any action, since the browser market is in a different, more competitive situation than when IE ruled.
As one of the most used tools, I like to have a level of customization that isn't found in the common defaults like Chrome and Safari; think Eudora and Firefox. On iOS, iCab is the one that comes closest to replicating such an experience, and is well worth the cost. But it can be infuriating when links invariably launch Safari unintentionally, because iOS doesn't give users the power to choose a default other than Safari, even if those users are a minority.
