I read about this when I first discovered GrapheneOS, and it looked like it. And it may be partially correct.

But on the other hand, I have read a lot of "drama" between e.g. /e/OS and GrapheneOS, and more often than not, it looked like GrapheneOS was criticising actual limitations of /e/OS and /e/OS (a mix of the community and official comms) seemed to be the one being unfair.

GrapheneOS generally is pretty direct at saying stuff like "their approach is strictly less secure" or "they are often worse than Stock Android", and I understand that this is not good publicity for Murena. But I am yet to see one of these claims to be wrong: all I can say is that the tone is very direct and could offend the /e/OS people, even if the claims are true.

On the other hand, instead of just acknowledging and trying to explain why /e/OS may be a good choice (e.g. if you happen to own a phone that is not a Pixel and that is well supported by /e/OS), I have seen actually wrong claims from /e/OS against GrapheneOS (sometimes downright technically wrong about security/privacy). And while GrapheneOS is quite exemplary with their support (if your phone is supported, then it's best in class), I have run /e/OS on a couple of phones and I have seen by myself that some of the security updates were 3 years old while the Stock Android was actually up-to-date.

So yeah... I get that it's a sensitive topic, but I feel like there is more a long history of people accusing GrapheneOS of accusing people, and I'm not anymore convinced that this is actually true.