As @WA suggests PWA's are JS-apps that can be used offline in a browser. You need JavaScript to instantiate the Service Worker which caches the request, without JS and in turn the Service Worker you no longer have a PWA.

PWA's are something that Google is pushing pretty hard right now, to me that suggests there is becoming less of a concern around JavaScript being turned off than previous years.

https://developers.google.com/web/progressive-web-apps/