I can get a cheeseburger delivered, or there's a dozen places within a 15 minute walk to get one. I can hardly leave the house without seeing an ad for one or some other fast food item on the side of a bus. I can't avoid being hungry, but I can leave my phone at home.
Sure it's a matter of degrees but I don't see a bright line between McDonald's and tiktok. Both want me hooked on their product. Both have harmful aspects. Both have customers they know are over-indulging. Why would only tiktok be liable for that?
If people never felt full from food, food was always instantly available in your pocket, and food costed no money to obtain, I believe McDonalds and TikTok would be very equivalent. Likely McDonalds would even be far worse since people would probably be dying to it daily.
That's the bright line. The lack of any barrier to entry.
If I had to walk for 15 minutes or pay a hefty delivery fee to access social media, my usage would be massively lower. If there was a cheeseburger in my hand all day every day I would be a lot fatter.