Those execs were also using the tactics to addict adults, and while they may have targeted teens, the problem is, at its core: humans. So no amount of nannying by either the company nor the government will solve this issue.

Who would be responsible if a child developed alcohol addiction? A nicotine problem? Any other addiction?

Exactly. The same people that should be responsible for giving them unfettered access to an internet that is no longer safe. Even adults have to be wary of getting hooked on scrolling, and while I agree that the onus is on the companies, it has been demonstrated over and over again that they will not be held to account for their behavior.

So the only logical choice left that actually preserves freedom is for parents to get off their ass and keep their child safe. Parent's that don't use filtering and monitoring software with their children should be charged with neglect. They are for sending a kid into the cold without a coat, or letting them go hungry, why is it different sending them onto the internet?

And to your last point: You are dead wrong. No government anywhere in the world has demonstrated that they have the resources, expertise, or technical knowledge to solve this problem. The most famously successful attempt is the Chinese Great Firewall, which is breached routinely by folks. As soon as a government controls what speech you are allowed to consume, the next logical step for them is to restrict what speech you can say, because waging war on what people access will always fail. I mean, Facebook alone already contains tons of content that's against its terms of service, and they have more money than God, so either they actually want that content there, or they are too understaffed to deal with the volume, and the volume problem only ever increases.

So in my view, you are the one against freedom by advocating for the government to control the speech adults can access for the sake of "protecting the children" when the actual people that are socially, morally, and legally culpable for that protection are derelict in their duties.