📵 How to Turn Off Write with Siri
Short version
Go to Settings > Screen Time > Content & Privacy > Siri and turn off Writing Assistance.
Rambly version
I've been using the Mac and iOS 27 public betas for a while. They've been quite stable (though your mileage may vary) and there are many welcome improvements and refinements.
I have also, somewhat reluctantly, been using the new version of Siri. Functionally, it's a vast improvement over the previous version I was using—I skipped the version that shipped with the '26 operating systems—but that's not a significant accomplishment given how bad Siri was (and still is on my HomePods).
The big general downside of the new Siri is that it's heavily entangled with generative AI, and I want to keep my use of generative AI as close to zero as possible. Thankfully, I don't use Siri for much, and a lot of what I ask of it doesn't involve generative AI (home automation tasks, setting timers, simple math, etc.).
However, one specific downside of the new Siri is that there are now places on my iPhone and Mac where I see prompts to use aspects of Siri I'm not interested in. The most frequent and most visible of these are the "Write with Siri" prompts hovering around text fields and the onscreen keyboard.
The good news: you can turn off Siri's writing assistance features entirely. The setting probably isn't where you'd expect it to be, and I couldn't easily find it by searching inside Settings, but if you go to Settings > Screen Time > Content & Privacy > Siri you'll find a Writing Assistance setting you can turn off. This setting is in the same place on both iOS and macOS, and once it's off, all of those annoying "Write with Siri" prompts and UI elements will never bother you again.
There are some other adjacent settings in there that might also be of interest, such as Broad World Knowledge, Image Creation, and more.
Enjoy!