> Also, big companies can choose to run their own models on their own hardware and get better security and privacy as the data doesn't need to leave their own premises.

Yes, and then they would be reinventing the company owned data center that most big companies have just spent over a decade moving away from. I don't think companies will do that when there are multiple vendors competing to provide that service at what are quite reasonable prices when you consider what paying a human for similar output would cost.