"$unhealthy_thing is not subject to restrictions, therefore $other_unhealthy_thing should also not be"? lol. lmao, even.
Should we let children purchase cigarettes? Alcohol? Cannabis? Cocaine?
The BMI epidemic in America tells me maybe we should ban sugary drinks.
At some point, society draws a line between what it deems acceptable and what it does not. In two generations it is virtually assured that we/our grandchildren will look back on Facebook and TikTok the way we currently look at the tobacco industry. The way I know this is because the CEOs don't let their kids dogfood their products. Famously, Steve Jobs wouldn't let his kids have an iPhone. Mark and Cecilia didn't let their kids use socials.
These are bad products designed to be deliberately addictive, and it turns out they're really only good at making people feel shitty and giving teen girls eating disorders.