I have a PWA (https://journalisticapp.com) published in the PlayStore as TWA (https://play.google.com/store/apps/details?id=com.journalist...) via bubblewrap. It has many users and people love it, many don't realize it is not a native app. But I struggle since a long time to find a good way to monetize it.
First of all, there is no good guidance about the topic besides some clips about the Digital Goods API and it only works for recent Chrome. How do deal with users that use a different browser or an older version? Is it ok to check if the API is available and if not use Stripe? No info about that... It can be pulled off, but UX will definitely be bad or worse.
Then, there is the problem with complex backend logic and accounting, I have to deal with two scenarios, did the person use Play Billing or Stripe to purchase? What if he used Play Billing and then wants to manage their subscription in the browser or other way around? It would be amazing if either Play Billing could also handle purchases on the web, or if Stripe could detect TWAs and automatically send 15-30% to Google for doing nothing.
Also, what about testing? How can I test my Digital Goods integration if it is only available within an Android app and not in my PWA? Am I supposed to publish an app that points to my dev server?
If Google was really serious about PWAs and Trusted Web Activities I think they should allow developers to use 3rd party payment systems (in TWAs only) until all of the issues are resolved and have solutions, instead of being like "ya we don't know either, you figure it out, but you can't use Stripe". As TWAs are only a miniscule fraction of TWAs in the PlayStore it won't even make a hint of a dent into Google's revenue, but it would allow developers to seriously pursue a PWA solution over a native one and therefore allow Google to see if it is viable and worth putting serious resources into.