I would guess it's the same mechanism as used in gambling , gaming and social media to addict the user: variable reward.

For some reason if you are given a reward with unpredictable interval in some specific context, this will create a dopamin kick in your brain.

So I would say you are not addicted to the news as such, you are addicted to the dopamine kick that picking up an occasional interesting news-article from the endless queue creates.

Slot machines, games with surprise reward loot-boxes, doom-scrolling social media - they all utilize this simple neurological hack.