"[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
Yes agree on that. Linux needs more standardization.
It is big problem, because it lacks the structure somehow. If there is easy tooling for app development, as Flatpaks with all the modern security practices (safe language, portals, modern GUI, Wayland, Accessibility APIs) then developers could easily follow these rules and create good apps more easily.
Currently app development is not easy and thus also very random.