Don't worry, the current hardware is already compromised.
Wait. Yes worry.
GrapheneOS users also lose the single-party accountability you get with a stock Android phone. This is all very bad.
Discussion
Do you have evidence that the current hardware is compromised? I don't mind you making the claim, but I want to see evidence to support it.
4G LTE / 5G networking require proprietary components
Modern chips in general have transistors too small to audit properly (we can make new chip designs faster than security auditors can analyze them)
Things like this compromise security for end users inherently