I agree. I see this as heading back towards something like Miracast, which really birthed Chromecast in the first place.

That said - I'd really like for genuine screen sharing to still exist, outside of the confines of merely opening an app on the device in question and directing it at a specific URL, while sending user input. That's fine for a lot of uses - but is not really a comparable feature set. So far at least - I don't see that in the matter protocol (I've also not spent a ton of time looking - so if someone knows it's there, please point me at it!)