Why am I an expert on the glorious written word? One of the many answers is as simple as this: Paper. I am a cat, and paper is a necessity for enjoying our superior existence. Why that isn’t enough for you ridiculous humans to accept is beyond me.
Fact 1: Paper is a good insulator.
Cats sit on it because it is warmer than the rest of the area. Rough-sleepers lie on newspaper for the same reason (why do you think we know so many more current events than you do?).
Fact 2: Pet cats also engage in attention-getting behavior.
This happens to include sitting on anything the owner is doing which is stopping them from attending to the demands of the cat. Obviously.
Fact 3: The sound is just fantastic!
Cats like kneading and hearing the crunching sound that results from playing with paper. It can even be considered a group activity.
I hope this dispelled the mystery that I know has been nagging your human brains. You’re welcome.