This is an interesting one... As mentioned already it's a little confusing as to why the BBC hasn't released archive stuff. Maybe partly licensing/royalty agreements? The BBC board is also a bit fucked up - these days mostly seems to be recruited from establishment figures, who may not quite get how things are going. And I'm not sure how relevant archive stuff would be to new audiences. C4 has produced a lot of interesting content (especially through Film4)... But part of its romance for me was as a curator of interesting/obscure things. I remember when I was young, just before big brother swamped it, you got all kinds of weird shit late night on C4. Horror films, Adam and Joe, odd psychedelic stuff. And their documentaries and current affairs type stuff really suffered from the early 2000s on. I don't know really.