Renewably3997 I don't like the fact that I'd be utilizing SMS so much more than I do now but I really have no idea what sort of data Apple is sending to themselves every few minutes and it bothers me that the iPhone is constantly communicating with Apple even when I'm not using it.
GrapheneOS:
you control what is sent over sms
you control what apps/services can access
no background communication from the OS
Ios:
iMessage is private from certain parties
limited control over what apps/services can access
full background communication from the OS
i would posit that as long as you take the necessary measures when communicating over sms, you have much more control which enables much better privacy with GrapheneOS. I am a former iphone user, am completely happy with GrapheneOS and encourage you to take the step if you feel you would benefit.
Good luck on you privacy journey!