The thing I really liked about Tiktok originally was the departure from the perfectionism of Instagram, and people being ok with participating in the dance moves and trends. It was pretty positive. The thing is once you have an engaged audience sometimes you might want to keep them captivated (and their attention farmed to resell ads to).

With that being said, I don't know if McDonalds is not a really usable comparison.

McDonalds is not an endless conveyor belt of food arriving in your hands 24/7 and beeping and buzzing you when it's not to learning how and what to put in front of you to keep eating endlessly until you can't eat anymore.

There's more useful studies that doomscrolling and shorts literally decrease brain size, increase depression, and lead to dopamine exhaustion.

Short Video players are digital slot machines. They seem to be designed to let people keep using it who might not be aware on how to build up defences, or of defences are needed. In a casino many of the things the games machines can and can't do are legislated by law. It might be surprising to learn how many of those things out right, similar to it, or unique to it can happen on a phone without circumstance. Casinos will also remind you to gamble responsibly, and be able to ban yourself if needed.

The line is really simple for kids - screens loaded with bright colors that are constantly changing with many layers of sounds from ages 1-5 pretty harmful at overriding their senses. Then, there's other content traps from there. The recent moves to schools that go screen free (or greatly reduce passive consumption) is critical. Putting a chromebook in front of a kid for 8 hours isn't always progress.