Russel said that Apple's iOS browser (Safari) and engine (WebKit) are uniquely under-powered. Consistent delays in the delivery of important features ensure the web can never be a credible alternative to its proprietary tools and App Store.
Russel has cited an example of this by mentioning Stadia and other cloud gaming services which Jobs Mob refused to be available on the App Store and pushed them to use the web instead, which requires Apple to allow gamepad APIs so controllers can be used with these new web apps.
That is a function that other browsers have offered for a long time except on iOS.
Writing in his bog, Russel said that if Apple had implemented WebRTC and the Gamepad API in a timely way the game streaming revolution now taking place might have happened sooner?.
He said that it was possible that Amazon Luna, NVIDIA GeForce NOW, Google Stadia, and Microsoft xCloud could have been built years earlier. It's also possible that APIs delivered on every other platform, but not yet available on any iOS browser (because Apple), may hold the key to unlocking whole categories of experiences on the web.
Currently, iOS browsers lack push notifications, standardised Progressive Web App (PWA) install buttons, background sync, and numerous other tools that make it easier for developers to make fully functional web apps.