Because it's now cheaper and more cost-effective, and if they can get away with it, saves them tons of money. Note: I don't think companies are likely to do this, but being able to do this without AI is not sufficient reason to dismiss the possibility. It's the same reason people who wouldn't steal DVDs from a store would pirate movies online. Much harder to get caught and easier to do, so this new way of watching movies for free became popular while the previous method was not.