Earlier quoted context omitted.
Last weekend my wife and I wanted to watch the movie Goat. It was pretty recently in theaters, so we didn't expect it to be on Netflix. We searched HBO Now, Hulu, Starz, and all of the other video streaming services that we have (and pay money for!). We found two options - rent it on Google Play Movies, or rent it through Amazon Prime. Now, we wanted to Chromecast it, and Amazon (to the best of my knowledge) does not…
There are two issues here, the fragmentation of the services, and poorly implemented services. I have really really tried to use Google Play for video because it seems to work on the broadest array of devices, but the service itself is a second rate experience. Too many clicks, laggy unresponsive UI, silly JS driven pages that require reloading in order to start working again... I too really want to do things the way…
Netflix and Prime are finally acceptable on Linux thanks to Pipelight but that solution's not for everyone.
If you want a single settop box, you might run PI with XBMC/Kodi but you can't get DRM'ed things on there. So you need a Roku or AppleTV for your DRM, a chromecast for things coming from a PC, and you still need a Kodi for your personal needs.