27 years ago we didn’t have children spending 90% of their waking hours staring at network connected devices.

Only the nerds did that and it was in a computer lab. And they knew enough about keeping up appearances to hit Alt-Tab when an adult was getting close.

Maybe they are all relevant upon full scrutiny, but that isn't obvious to me (albeit IANAL). I know what my kids buying a potentially violent video game is like, and I know it is very different than participating in social media. And regarding the CDA in the 90's, take some of the opinion:

In order to deny minors access to potentially harmful speech, the CDA effectively suppresses a large amount of speech that adults have a constitutional right to receive and to address to one another. That burden on adult speech is unacceptable if less restrictive alternatives would be at least as effective in achieving the legitimate purpose that the statute was enacted to serve.

That's just me grabbing a snippet from Wikipedia, but it seems like a different issue than the impact of social media and whether it should be allowed by minors w/o parental consent.

Those rulings all differ from the current situation in multiple aspects. For example, it was determined that the VG industry is effectively self-regulating. It's questionable that Tiktok is effectively regulating itself with respect to minors. And the CDA required the government to unconstitutionally determine decency, whereas the Florida law is about access.

But of course the elephant in the room is that the makeup of the Court has changed in a markedly more conservative direction and has proven itself not averse to revisiting previously settled law.

What is constitutional about releasing psychological warfare techniques on children? Because that is what these social media platforms are doing.

Maybe those rulings were wrong. The Constitution says to "promote the general welfare".