There is clearly a use case for keeping the whole UI. But it is the major use case and should the whole product philosophy be based on it ?
I feel there will be more sites where the URL won't matter or where the user will prefer simplicity to control.
I use Google Maps 99.99% in PWA mode and never mourned the lack of the URl bar, especially as I can open the site in normal browser mode anytime I ever want the full controls.
I'd be fine with a 2~3 click operation to get the URL.
Which is basically how it works in Chrome in PWA mode: a few basic actions (get the URL, print, cast, adjust zoom etc) in a menu, and an option to punt it to the full chrome if needed.
I feel there will be more sites where the URL won't matter or where the user will prefer simplicity to control.
I use Google Maps 99.99% in PWA mode and never mourned the lack of the URl bar, especially as I can open the site in normal browser mode anytime I ever want the full controls.