I grew up being accustomed to having the TV as background noise but stopped watching it when I moved out. Now, when I visit my parents, it's honestly quite difficult for me to focus on conversation - there's a machine in the corner making deliberately attention-grabbing sights and sounds. So I think your experience is normal & I empathise with the generation that complained about TV ruining family life.
Same and same and same, but I know exactly why I won't leave the telly on - I'm very susceptible. It grabs me. Even though I have no interest in ads or even 95% of programming. It's not a pleasant feeling.
If Millennial still = young then yeah, YT or something in background on TV, doing something on laptop (dev, or photo editing or other) and then occasionally phone over laptop as well to reply to chats and stuff.
I would kill for some decent high res wide fov AR glasses.