We cannot generalise that any of them is more profitable. Some casinos make more money than exchanges and vice versa. If we consider how much casinos spend on advertisements or promotions, you might get a glimpse that they are making enough money. Binance was fined more than $4.3 billion by the US government in fines and forfeited property, which means they are making high profits. The profitability of these businesses will depend on their size and management.