This is all demonstrably false and goes against the available evidence.

Here’s a good Lancet study that investigates ultra processed foods by sub-type and looks at the health impact. Those who are meat and sugary drinks with artificial sweeteners had the highest incidences of cancer. Those who ate high amounts of ultra process plant based alternatives had a lower cancer rate than the base population. Believe what you want, but when it comes to cancer, eating ultra processed plant based products is better than meat.

I agree that it should primarily be a parents responsibility to keep kids off social media. But the big problem with social media is that a large proportion of young children don’t want to be on social media and recognise the detrimental impact it has on them, but the fear of missing out or being excluded is what keeps them on it. it then becomes a collective action problem, to get them off it you need to get a lot of their peers off it as well. There are movements where groups of parents try to do this, but reaching the critical mass necessary to do it is difficult.

Hopefully the ban keeps a large number off to reduce the pressure on kids to be on it and at the same time the parents can do their bit as well.