I’ve not seen Euphoria, but drugs, drinking and sex plus underage clubbing were all things that happened at my schools between 15-18.

A drama like Euphoria is of course going to be way over the top regardless of setting.

But I do agree casting 25year olds (zendaya is 29 years old) feels bizarre but what American TV has always done. Presumably it’s to do with experience given these are expensive shows that need to work to strict production schedules - it’s understandable they’d want a cast who have been proven to be reliable and also are not restricted in the hours they can work. Also age consistency matrers - once you have one 25 year old cast member all of them need to be the same age or it looks disturbing with a mixed age cast set in a high school.

I suppose profile may matter too - Zendaya was already famous; the pool.of famous 18 year old actors is smaller than the pool of 25 year old actors.

I agree they could just not set it in a high school but then the specific dynamics and stories they want to tell would not be available. High school is a strange time - especially in the US but also globally - where people are on the cusp of adulthood (16 in many places, 18 in the US), yet totally restricted by the law, family and school. It’s a perfect setting for conflict, which makes drama, and it is universally relatable as almost everyone went to school.

Meanwhile if you set something 19-25, it is no longer universal. About 50-60% of people in rich countries go to university / college. And those institutions massively vary from community colleagues, poorer universities, up to elite places. Meanwhile 40-50% do other things.

So yeah, I get that it feels bizarre that shows set in high schools are all 25 year old actors but I think it makes sense why, and setting things in high schools make sense too. These shows obviously make money and have a wide audience., even if it’s not really my personal taste.