I have kids. We’re social. Spend a lot of time meeting new parents all the time.

I have never heard of a 5 year old with a TikTok account.

I think your cousin is so far into the outlier end of the parenting tail that nothing they do is going to make any sense in the context of common parenting practices.

Alternative theory: your bubble is small, and you socialize with parents who have similar values to your own. And I'm gonna guess that your income or wealth is in far outlier territory. I've seen kids raised like this; in my generation the concern was kids glued to TVs all day, and some of those kids turned out okay. But in my family, it's the parents who grew up glued to screens who are raising the most screen-addicted kids.