In all seriousness - which half of the new Google WEI divided web will you so confidently declare "That's not the web" for?
Because this is the half Apple broke off to sell as iOS apps. A domain that is entirely exclusive to apple, and requires all sorts of hoops to gain access to (including purchasing Apple specific hardware).
Further - they enforced that domain by strictly locking down down the capabilities of literally ANY browser a user might try to install on iOS. Because otherwise users might have chosen to use a progressive web app and Apple wouldn't get their fucking 30% store tax.
The problem isn't that other clients exist, a company that wants to have complete control of the UI can make an App that ensures it, they can deep link into it - no problem.
The problem starts when the main platform used to consume the web starts having specialised features which make some websites work only on this one platform because the developers build specifically for this one platform.
And no, this is not the same for the AppStore because the AppStore is not the web. Apple controls a minority share of the market, its not universal and it's not supposed to be universal - its a an additional distribution channel of content to Apple specific devices.
