"Most important piece of furniture" is a heavily loaded ideological claim. It points to the rampant American culture surrounding media consumption. I've been pretty stunned during my travels to find that it's really only Americans who obsessively talk about or reference TV shows and movies in their small talk. No other culture seems nearly as interested, and some actively discourage it in favor of more real, personal…
I think you may be engaging in a bit of axe grinding here! I agree that the sofa is one of the post important pieces of furniture in my home [1], but for reasons that have nothing to do with television. There is no TV in the room! But it is still where I spend the most time sitting during downtime, reading books, talking to my family, etc. And when I have friends over, we're either there or at the dining room table.
[1] For the title of the most important, I might have picked my bed. But that's a quibble.