The payoff of consistency is worth it. It buys you a sustainable pattern, which is golden.
The other problem is how busy people are - how many people can genuinely say nowadays that they're a full-time parent? Everyone I know (which, granted, isn't many) have both parents working part-time, so their kids go between one or the other parent, grandparents and day care. But the ideal would be that one parent stays at home, takes care of the household and is present and able to give their children attention when they need it.
But if you're a parent that just came home from work and needs to do housework, then it's very tempting to be able to leave the kids to their own devices. And sure, that doesn't need to be devices per se, but it is a pacifier of sorts.
But this is what the powers that be don't want, because one parent not working is not optimal for the economy.
With a second it's practically impossible. We'd need extra childcare (and more floorspace where we live!) to trap him in a different room while the first is watching TV. Taking TV away from the first would be very hard (you're right that it's hard to withdraw once it's routine) but also not something I'd want anyway.
I'm not convinced that it necessarily expands out once it has a foothold. We have a pretty well defined TV time (before dinner) and it's easy to say "yes you can watch that show ... when it's next TV time".
When kids are older (maybe 4+), they also really enjoy listening to audio books (I'd try to avoid anything based on TV shows though, they are quite terrible and obviously not designed for the listening medium). This also works great for car trips.
(There seems to be a literacy crisis happening in real time right now because kids grow up with less reading/writing and more viewing/listening/recording than preceding generations)
I wonder if those kinds of things still exist in some format.
What the f? how about 4 or 5? They can listen to audiobooks in the car
Im 40, or tv was not in 'the living room'. Just because there are families who have it even running as background noise, doesn't make it normal.
Its also a poorness indicator though
Said imagination died for the most part at some point in the past 30 years but I remember it well enough.