[vitus]

> It's quite possible for one broadcasters 480p30 to be a higher bitrate than another broadcasters 720p60

Yes, I don't think anyone's disputing that.

> I remember watching the last season of Game of Thrones on one streaming provider, which topped out about 3.5mbit but claimed it was "1080p".

Why the scare quotes? That's a perfectly reasonable bitrate using modern compression like H.265, especially for a TV show that's filmed at 24 fps.