Nickelodeon literally was raising kids from 8am until Nick at Night. It cant be compared to a collection of cartoons. Nickelodeon paved the way for channels to exist that catered exclusively to kids.
Classic shyt like You Cant Do That On Television, Wild and Crazy Kids, Nick Arcade, What Would You Do, Guts, Double Dare, All That, Are You Afraid Of The Dark....etc.... Those are groundbreaking type shows.
Hate to say it but if you werent a kid when Nickelodeon was in its prime then you cant grasp how much that channel changed everything. That was one of those generation defining periods.