Both things can be true. Parents can share responsibility. But it is also the case that Facebook actively suppressed research that showed that children using their platforms experience emotional harms. It is also the case that around the time you were in elementary school discussions about children’s programming had been ongoing for years and eventually regulations were put in place[0].

0: https://en.wikipedia.org/wiki/Regulations_on_children's_tele...

I can agree that I think they acted to harm society knowingly. I used to think regulation could help and maybe it can, but if there were some way to shape the culture to value, for example, educational tv programming, I think that would be the most powerful influence on tech/media companies. Regulation could serve to inform parents “this programming/platform is known to rot your kids mind” like a nutrition label and some day hopefully parents will be more likely to disallow it like some do knowing how much sugar is in sodas.