I don't think that would happen. I don't have much faith in Apple's abilities in this area, and their incentives are structured such that the less viable web apps are as a replacement to native apps, the more money they get from their 30% cut.

Again, your arguments would make sense if my opinion was: "good guy Apple valiantly defends the open web from Google out of the goodness of their hearts". But that isn't my argument. I don't care whether Apple could compete with Google if they tried. I care whether Apple would compete with Google, and they wouldn't.

> I mean, keeping one monopoly at bay (Chromium) with the other (WebKit requirement) isn't really how this is supposed to work, right?

WebKit isn't a browser monopoly, it has less than 20% of the browser market share. That 20% share is big enough to push web developers towards making websites work in browsers other than Chromium, but it's not big enough that there's a danger of web developers thinking, "everyone uses WebKit anyway so we won't bother testing on anything else".

Sure, it's a monopoly on iOS, but I don't see how this is relevant to my argument. The web is more important to me than iOS is.