But we're not seeing some screen sharing of the android app. We're seeing a completely separate web app, running in the browser. The only difference is from where it is syncing its messages. It's a real web app.
And it works this way because chats are only stored on a single "main" device. Then they sync to connected peripheral clients as needed. I think that's a good thing, to be honest. I don't see that as a negative thing. It's not stored on any server (I assume(?), due to the current behavior), which is nice.