how has it NOT been harmful?
I'm more inclined to believe my parents did the right thing by limiting TV time and commenting that most of it was rubbish. And I presume like many parents in Silicon Valley, I'm going to fight tooth and nail to keep advertising and most of this stuff from my kids.
The funny thing is, if you're not brought up around it, if you learn some math and statistics, and then you suddenly go somewhere exposure is considered normal, you almost have a physical or psychological revulsion to it.
Ads become frustrating and unacceptable intrusions. casino floors are sad, boring, pathetic and dystopian. mobile games look like drugs foistered upon an underclass, etc.
At least with big TV at the time, programming was so limited (at least in my country), you had maybe 2 to 3 hours per week of anything that would fit a genre worth watching. But even with that restriction, I know a large number of people who deem that the TV should be on even if there's "nothing to watch". I just can't write that sort of behaviour off as not being dysfunctional, it's just that we've culturally got a general acceptance of very specific types of dysfunction...
And what about rates of obesity? I'm not saying TV is solely to blame, but are we going to pretend that screen time and such programming (on demand or otherwise) is a blameless part of our culture?