the solution is to remove the bits of those apps that are harmful to children (and adults): the algorithmic data feed, the infinite scroll, the engagement tactics, the advertising
So, for instance, pornography and gambling should be 100% illegal? Or at the least, all social media sites should censor any discussions that aren't child-appropriate?
No, I don't think pornography, or arguably gambling has the same "manipulative addictiveness" hooks in the same way. The equivalent for those would be something like, if a company every time you opened their porn app had your phone emit a silent puff of nicotine (just... imagine that existed for the sake of analogy). It's about the difference between going on to Facebook and seeing your feed of your friends' posts and seeing your feed of posts selected based on content expected to ragebait you into responding.
They're saying we should remove the features in general because they're anti-features harmful to everyone, and focusing on children distracts from that fact.
This conclusion is up for debate, but that's what they mean.
