Why can’t I turn off Show my caller ID?

Hi Insahamed,
Thanks for using the Apple Support Communities. I understand you are having some issues with the Caller ID setting on your iPhone. Caller ID is primarily a carrier-side function. If you are seeing that your Caller ID is turned on, but it is dimmed out so that you can't turn it off, you may want to reach out to your carrier and see if they require Caller ID to be active.
Call forwarding, call waiting, and other call features on iPhone - Apple Support
Regards.