Because not everyone had cable. Nor did they need it.
In no particular order.
PBS / Via cdn.smosh.com
The Magic School Bus (1994-1997)
It was Ms. Frizzle's world, we were all just living in it. Tell me you weren't disappointed by your school field trips after watching The Magic School Bus.
PBS / Via youtube.com
The Big Comfy Couch (1992-2002)
Okay sure I may have been terrified of Loonette's doll, Molly, but each episode had a moral important to young viewers. If you learned nothing else, I hope you learned the importance of stretching.
PBS / Via youtube.com
Cyberchase (2002-2014)
Cyberchase was cool because it taught viewers problem-solving and math skills in a fun and interesting manner. It proved that kids can be smart AND have fun.
PBS / Via youtube.com