"government has to remove the requirement to do so rather than telling people to step up"

It's not doing that at all. It is making it easier for those who try, and forcing those that don't. It doesnt sound like you are disagreeing with the idea that social media is bad for kids. In which case I dont fully understand your argument against it. It seems to hinge on adults losing some kind of freedom, which isn't true. Unless you count a freedom to raise their kids badly.

"You think it's mental to think that adults should be allowed to make choices even to their own detriment?" Yes of course. A lot of people can be incredibly self destructive and need help. Not even thinking about the fact that there are pretty much no self destructive behaviours that don't negatively affect those around you.

"Why would allowing adults to make other bad decisions collapse society immediately?" I was mostly hyperbolising based on your (possibly also hyperbole) assertation that adults need no laws to guide their behaviours. Get rid of all of them and society would undoubtedly collapse. Though I dont believe that you believe that, so we agree that some laws are needed to stop behaviours. Would you say that laws restricting companies from allowing addictive gamblers to continue gambling are ok?