Apple seems to have persuaded OpenAI to work for exposure
Briefly

Apple partnered with OpenAI for GPT-40 model in iOS 18, iPadOS 18, and macOS Sequoia, offering advanced AI features like writing tools and Siri enhancements without additional charges.
By promoting ChatGPT Plus to Apple users, OpenAI can make revenue, with Apple planning to profit from AI through revenue-sharing, potentially impacting its Google search deal.
Read at Engadget
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