Prime example: Dr Who. This was the era of Tom Baker as the Doctor. Honestly, it was amazing. But there were other shows that were just plain goofy like The Goodies and Monkey. On the sci-fi front you had Blake's Seven, which was way ahead of its time in moral complexity. To this day, Avon is an amazing character.
We saw very little American TV. Sesame Street was a notable exception. At the time this even dealth with complex issues (eg the actor who played Mr Cooper died IRL and his death was on the show).
As I got older you got into shows like Grange Hill, which actually dealt with issues like a kid dying of a heroin overdose.
In my teens I got into more adult shows like Yes Minister (which, to this day, is amazing). We had in-depth news program that was of exceedingly high quality (ie Four Corners and the 7:30 Report) that included such gems as [1] (referring to the Kirki [2]).
But what happened in the 1980s to the BBC in particular was that children's TV got really dumbed down. Dr Who was viewed as "too scary". So all this innovation basically disappeared under the guise of the road to hell is paved with good intentions.
It wasn't really until the 2000s that TV recovered from this and even now I believe even now that children's TV is simply awful. None of it seems to be intellectually engaging at all and certainly not "adventurous".