How come cartoons never die?
Do you mean the characters in the cartoons, or a serialized comic strip?
characters in cartoons
There’s only one thing that can kill a toon: Dip.
The character can die, at least for that episode, if it’s the last “skit” in the episode. For example: in one Road Runner cartoon, Wile E. builds a rocket sled to chase down the road runner. Only it jumps it’s rails and shoots straight up into the sky, where it explodes like a skyrocket. We then see a new constellation in the heavens, The Coyote. Clearly he has gone on to something better at that point.
What are you talking about? Superman has died from Virus X and he died again recently. As I recall, he has died several times.
In the comic strip “For Better or Worse”, a dog and a grandmother have died. Of course, that one is more reality based than “Garfield” or “Road Runner”
Sure cartoons die.
Fritz the cat was done in by his ostrich girlfriend (got an icepick in the head). His cartoonst, Robert Crumb, didn’t like the animated movie made about him.
Bob the Angry Flower has been killed about three times already.
As Simpsons fans will tell you, Lisa’s musical hero, Bleeding Gums Murphy, died – in fact the whole episode was about his death. I think one of their pets (Snowball “I”?) died too. Right?
Everyone dies in anime, heh. In fact, it’s odd to see a show where someone DOESN’T die. 
Cow & Chicken should die…How can anyone watch that?
- Tsugumo
The premise of the OP having been proved false, I’m closing this thread.