A nice post about PWA from Mike Elgan. I am not sure about Microsoft's goal with PWA, but I think our's is pretty simple: we want users to have access to content and functionality instantly and in a way they expect to be able to interact with it on their devices. The web should reach everyone across every connected device and a user should be able to access in their preferred modality, as an app if that's how they expect it (mobile, maybe), or voice on an assistant etc.
We're still a long way from the headless web, however, one thing really struck me in the article:
Another downside is that PWAs are highly isolated. So it’s hard and unlikely for different PWAs to share resources or data directly.
Sites and apps on the web are not supposed to be isolated, the web is linkable, indexable, ephemeral, but we are getting more siloed with each site we build. We are creating unintended silos because the platform doesn't easily allow users to get their data in and out off sites easily. I'm not talking about RDF or anything like that, basic operations such as copy and paste, drag and drop, share to site and share from site are broken on the web of today, and that's before we get to IPC between frames, workers and windows.