Well they still don't allow PWAs in the Play Store without bundling them as full apps and going through the regular publishing/update/approval process, which kinda defeats the point.
Which is weird as hell because treating PWAs as apps (from a mobile UI perspective) could be built in to the OS itself. Maybe there's some reason The Google won't do this, but OSes already treats the web as a real thing (integrated web views and such), so PWAs would seem like a next step to that.
It is built into Android. Go to twitter.com, log in and then accept the install prompt that appears. It integrates seamlessly with link sharing OS UI and jump lists.