"[GNU/]Linux being secure is a common misconception in the security and privacy realm."
https://madaidans-insecurities.github.io/linux.html
"[GNU/]Linux is thought to be secure primarily because of its source model, popular usage in servers, small userbase and confusion about its security features. This article is intended to debunk these misunderstandings".
Based on this, one should try to do as much as possible on a GrapheneOS device
The real point is not that Linux is less secure than often said but that "inherently secure" is not a thing, especially not when a network is involved. Your system can make it easier for you but you still have to look after your own safety.
That's pretty much what I have said
Yes; I was summarizing, not offering a differing viewpoint.