One of the main motivations for this law was pro-suicide and pro-anorexia content being pushed to teenage girls. In particular Molly Russell's death received a lot of press coverage and public outrage at tech companies. The coroner's report basically said Instagram killed her. https://en.m.wikipedia.org/wiki/Death_of_Molly_Russell

Of course if you get your news from HN then the motivation is actually something to do with limiting discussion of immigration or being dystopian just because.

But yes, if they could just name Instagram and TikTok they probably would.