This isn't difficult: TVs should not be "smart". TVs should be incredibly dumb. They should be screens for displaying stuff. That's it. Nothing else. No network connection of any kind, no apps, no software beyond that necessary to do basic setup of how that screen works: brightness, input selection, etc.
That would essentially force people to buy two devices - one for receiving content to display and a second to display it. All your solution does is shift the problem on to the receiving device. It wouldn't fix anything, and at the same time it'd increase the cost and complexity for the user (by a very small amount admittedly).
When I buy a computer monitor, I can pair it with any computer I want. I can upgrade the graphics card or processor independently of the monitor. I'm not locked in to a particular computer based on the features of the monitor I want. TVs should be the same. It could be as simple as a USB stick you plug in the back.