Cast your minds back
I find it much faster and easier to cast content from smartphone to TV, rather than navigate through the TV's laborious submenus and unintuitive button sequences to reach e.g. the YouTube app. All the TV needs to do is display anything cast to it. And if that's too hard, a £30 Chromecast or Amazon Fire dongle will fix the problem.
More importantly, a TV should last a decade or more. Any "smart" TV will be poorly supported within three years, let alone ten. (Just look at how few Android phones get OS upgrades.) So let's hear it for dumb TVs controlled via smartphone instead.