They should, but they won't. Apple's whole "It Just Works" pitch is predicated on them controlling the entire stack. The browser is such an important layer of t

They should, but they won't. Apple's whole "It Just Works" pitch is predicated on them controlling the entire stack. The browser is such an important layer of that stack these days that if they yielded that layer to third parties it'd inevitably lead to cases where some popular third party browser didn't work right with some sites or some other elements of Apple's stack. Which they don't want, because it undermines their entire strategic raison d'être.