The thing about a lot of these contestants is I find a lot of them look and act much older than they are.
My daughter has recently turned 21. I've met more of her friends than I can count and none of them look as old or act as mature as these contestants do.
Georgia looks her age without make up, and Dani is like an old head on young shoulders, but they are all so confident, self assured, and present as so much older than their years,
I don't think my daughter and her uni mates and old school friends are unusual. I think the kids on this show are in how they present themselves at such a young age. I get they are adults, but they are very very young adults, acting older than they are.