The problem is that the screen itself is a large, beautiful, and relatively expensive piece compared to everything that puts content on it. The price point makes it impractical to upgrade and replace on the same cycle as an XBox, Playstation, Roku, Apple TV, etc. Personally, I replace the screen every 7-10 years, and the connected devices every 3-5 years. Until the screens drop sufficiently in price to be replaceable in sync with the content devices, it makes exactly zero sense to cram more stuff into them. Especially when you consider the security issues.