The majority of iPhones don't support Apple Intelligence so the Writing Tools feature isn't available to most iPhone owners. You can create a shortcut for rewriting text using ChatGPT that mimic's the Apple Intelligence writing tools.

Apple Intelligence has officially launched with the latest updates for iPhones, iPads, and Macs. While the AI-powered features on iPhone with the iOS 18 update is getting the most buzz because — let's be real — new smartphone features are arguably one of the most impactful in our daily lives,

To use the feature, iPhone 16 users can press and hold the Camera Control button. Once in the Visual Intelligence interface, they can take a picture and ask ChatGPT about it. Alternatively, users can also perform a Google search with the image, similar to what Google Lens does, but in a more seamless and iOS-like fashion.