PWA's represent the very best opportunity to populate the Microsoft store and shrink the app gap.
If MS were going it alone with PWA I personally think it would fail, but given that Google and even Apple, to a lesser extent, are pushing PWA in their own right, it's looking extremely likely that this is here to stay.
I've used a few of them: Uber, Outlook, Cnet, Twitter and Youtube. It's very impressive and a great start.