I don't really have a problem with grapheneOS that calyx would solve. It would probably just make things worse.

My main issues are:

1) I am used to the iOS environment more than android

2) 95%+ of my contacts use iPhones so I can securely message with iMessage, only a quarter of them use signal. By using graphene, I end up with insecure/unencrypted SMS messaging with my contacts

3) I do not use icloud, i don't use siri, i use lockdown mode. I feel like with those settings, I have a setup that is probably equally as secure as graphene with some (but hard for me to quantify) privacy tradeoff since apple is probably still collecting a bunch of data on me