These days people are calling even basic stuff like Anora, and EEAAO as art films because they won Oscar.
For me these films are pretty grounded and understandable.
I always think art films as where they show random shit and you have to make sense of…Tarkovsky or Fellini for example.
Arrival, Midsommar, Manchester by the Sea,Call me by your Name…might be bit deep for mainstream audience. But they are not art films, they are pretty state forward stories with good quality filmmaking.