What are some ways that social media companies can limit or eliminate harm to children?

As you may know, the heads of the largest social media companies like FB and TikTok were in testifying yesterday on Capitol hill, in reference to harm coming to children who use their platforms. Specifically, children commiting suicide, being sold drugs, being exposed to child predators and being extorted by people who they have interacted with.

I have a teenage daughter and as far as I know, she has never experienced any of these things, although I am not naive and I realize it’s very possible she has experienced some things but hasn’t told me. I did tell her way in the beginning when she was using Instagram and doing online gaming to be cautious and I explained about catfishing, never give out personal information like where we live, etc. Never, ever send naked pictures to anybody. I continue to reiterate those things in case she gets too comfortable with anybody online. The school also talks to the students about online safety.

I know social media companies have minimum ages for users. In your opinion, what are some things that social media companies can do to eliminate or curtail harm being done to children?