There are a number of interesting use cases for PWAs, but part of Apple's fear is (potentially) many of their clients will migrate to PWA only, reducing App Store revenue severely.
Apple also loses all code auditing and screening, meaning they can't ban GPL licensed PWAs like they ban alternative Linphone builds (as they are GPLv2), Signal Private Messenger builds (GPLv3) and only the official developer can build and submit these apps to the app store.
Apple's GPL ban also effiectively mandates these apps having broad CLAs to ensure they can relicense the code for use in the Apple App Store.
Apple also loses all code auditing and screening, meaning they can't ban GPL licensed PWAs like they ban alternative Linphone builds (as they are GPLv2), Signal Private Messenger builds (GPLv3) and only the official developer can build and submit these apps to the app store.
Apple's GPL ban also effiectively mandates these apps having broad CLAs to ensure they can relicense the code for use in the Apple App Store.
Edit: removed bonus apostrophe