You obviously didn’t understand my post otherwise you would have addressed the actual point, rather than make an extraneous point about developer costs’
These stadiums are built because that is precisely what people want or expect when watching professional sport or other events.
Think of it this way: if the majority of customers, on the other hand, wanted to sit on hills then you would see such stadiums used around the world, in the majority. Outside of international cricket grounds (in the vast minority notwithstanding) you just don’t see them in a professional sporting context.
Now that doesn’t mean NS Oval, Leichhardt Oval and the like don’t have their place, but that place is purely on a local level. People watching local sporting competitions, paying entry fees of $10, buying a pie or a sausage roll and sitting on a hill on a picnic blanket for example.,