If you use another browser today even if it does use Apple’s engine, Apple’s not making search revenue from Google.
The second point is that it came out in the Epic trial that 90% of App Store revenue comes from games and in app purchasing. Those apps are not going to the web.
Third, if the only thing stopping great web apps is Apple, why aren’t their popular web apps for Android and why do companies that produce iOS apps still create Android apps instead of telling Android users to just use the web?