OpenAI isn’t allowed to blindly scrape iPhone or iCloud user’s data. They can only learn from whatever data the user submits in a query. And Apple forces users to consent to every single query that is sent to OpenAI. And that query compute is expensive.
Given that Apple built in a way for GPT pro licenses to be used, my guess is that selling the subscriptions is the real business angle.
Open AI will get data from those queries, but since it’s a query, it requires significant compute. Paying for compute for the world’s largest smart phone manufacturer is going to hurt if they can’t monetize somehow.