Just wanted to say same. I have used a Linux box as my Media Center and Home Server since 2008. Also have a chomecast dongle so I can steam from Android and Android apps. Not sure what else one needs.
Seems to me what one wants wants really is mostly a browser and ability to stream stuff from apps on your phone. Since the Linux box is a Media Center and Server it also has a lot of features a Smart TV would not have. Just do not see the value of a Smart TV.