They then realized that they could make much more money with locked-down proprietary apps that they could tax at will through their App Store. Since then Apple has blocked any meaningful evolution of web apps, to prevent them from competing with native apps.
The App Store was opened in 2008, and was a huge success in 2018 (https://www.apple.com/newsroom/2018/01/app-store-kicks-off-2...: “New Year’s Day Sets Record With $300 Million in Purchases”)
If “Since then Apple has blocked any meaningful evolution of web apps”, why did they add support for PWAs on iOS in 2018? (https://medium.com/awebdeveloper/progressive-web-apps-pwas-a...: “Safari is finally adding PWA features.”)
1) From a regulation standpoint, it's in Apple's interest for PWA's to exist; Apple has used the argument in court that PWA's are a viable alternative to it's App Store and therefore it does not have a monopoly on iOS "apps".
2) From a financial standpoint, it's in Apple's interest for the PWA experience to be sub-par.
And this is how we got here.
PWA’s were a brand new subsystem introduced in iOS 11 with substantial (yet not emough) ongoing investment since then.
The conspiracy theory still doesn’t answer “why have then been investing in PWA’s since iOS 11?”, if they wanted them dead they could have just removed them rather than doing incremental enhancements.