I recently integrated PWAs at our company. We offer a WYSIWYG-style editor for landing pages and integrated service workers mostly for SEO ratings and caching form submissions while temporarily offline (eg. on the subway). To me the whole thing is yet another clusterfuck of webdevelopment. Patchy support, governed by our "well-meaning" overlords at google and just a lot of non standard javascript magic involved. Just the way that the Install Prompt is handled is a good example. After some quite intransparent heuristic there is a "beforeinstallprompt" event fired. But you have to store that in an object and trigger it via an onClick on a button, otherwise the event gets intercepted.[0] I really hope that the standard will mature because the idea sounds really nice when you think about so-so mobile reception etc. but right now it's a bit of a pain still.
Apple just told w3c that beforeinstallprompt is bad and they will not implement it. Firefox won't too. So I really don't know what is going to happen going forward...
0: https://developers.google.com/web/fundamentals/app-install-b...