It's now possible to shoot 14-bit uncompressed CinemaDNG Raw on iPhone 15 Pro and Pro Max phones, though unfortunately this is currently limited to 1080p at 24 or 25fps, which means a heavy crop on what already are very small sensors. The app is called sr RAW, which is similar to MotionCam Pro but with a lot less functionality at the moment, and also it's subscription based
Hopefully they'll add more features fairly soon.
Here's a video I shot with the app yesterday. The quality of the footage and colours reminds me a lot of shooting raw with the Canon EOS M in crop mode.

Here's a video I shot with the app yesterday. The quality of the footage and colours reminds me a lot of shooting raw with the Canon EOS M in crop mode.