Where's the warning label for Facebook, Instagram, TikTok?
Usually there's a need for age appropriateness warning labels on things when a parent can't reasonably be expected to sit through an entire movie or play a video game to determine its age appropriateness. Most adults who are giving their kids access to a smart device, though, probably do have enough familiarity with Facebook to make their own determination as to whether or not they want their kids using it. It's also been possible for as long as these sites have existed, to do a Google search on professional opinions over age appropriateness of various social media sites.
I used the junk food as an example because the label doesn't specifically say anything about that if you kid pigs out on this non-stop and you keep replenishing their supply, they're going to end up with childhood obesity. The label just says that the product is mostly sugar, and a parent is supposed to connect the dots that it is only appropriate to consume in moderation. Some parents might even decide that giving sweets to their kids is something they'd prefer to avoid entirely.
I'm not holding Facebook entirely blameless here. They did the same dirty tricks the old tobacco companies did with trying to hook kids while they're young, but this time it wasn't something kids could get their hands on by dropping a few quarters into a vending machine. Parents willfully participated by buying smart devices for their kids.