Yeah, I still stand by telling kids you don't want them to follow you if they're legit too young for the site. To expand on that social media isn't a good environment for children under 18 anyway, especially sites/apps like Instagram and Tiktok where the point is to take pictures and videos of yourself. I always see teens on sites like that, and Twitter, posting all their info, including their age. They're mingling with adults, exposing themselves to situations only adults would understand, drawing attention to themselves. These kids don't get how easy of targets they're making themselves to predators and scam artists.
To me they shouldn't be on sites catering to adults, and talking to adults, unless they've been well educated in internet safety... as boomer as that sounds. Which most children don't get, parents are too busy or don't know nor care about that stuff, and there's no mandatory formal class teaching them how to go about using the internet. At least as far as I know.
In short. No, I don't think teens should be on social media, not unless they're well educated about it. Twitter, Instagram, Tiktok, whatever, are not good places for children.