My experience of TV in the 80s was that children's TV was limited. In the week there would be schools programmes and a slot for pre-schooler programming, then the after school slot until 5:30. Other TV was adult based and there was more emphisis from the BBC on the inform and educate than the entertain. More child-centic morning time on weekends and holidays.
The appeal of watching TV all day was low.
There wasn't the volume of high-paced, inane content that can be accessed through satelite/ digital and online (e.g. youtube) services. Some years ago, I bought some DVDs of BBC drama/ book adaptions I loved as a child and the pacing was very slow compared to current production styles.
Appropriately filtered TV/ screen time has its place (Cbeebies was a life saver during a hard pregnancy and long winter with a 2 year old!), but excessive screen time to the detriment of other activities, and low quality content is an issue.
With the young people I work with, their demographic hasn't changed in the past 20 years, but attention spans, impulse control and general "worldliness" has changed at a cohort level.
A comment I had from DS's teacher at a y7 parents evening was that it was lovely to teach someone who had interests other than gaming (and he certainly does love his gaming) but other than that (and football) a lot of boys that age have no wider interests in life, and that limits their creativity and skills for that subject. (Not helped by the SATs focused KS2 curriculum and culture)