Secure Operating Systems (Microkernels seems to be the future)
I am not satisfied with Linux's security and have been researching alternative open source OS for privacy and security
So far only thing that's ready to use is GrapheneOS (Based on Android) but that's not available on desktop (Though when Android release Desktop mode it may become viable)
Qubes OS is wrapper around underlying operating systems, so it doesn’t really fix for example Linux’s security holes it just kinda sandbox/virtualize them
OpenBSD is more secure than Linux on a base level but lack mitigations and patches that are added to linux overtime and it's security practices while good for it's time is outdated now
RedoxOS (Written in Rust) got some nice ideas but sticks to same outdated practices and doesn't break the wheel too much, and security doesn't seems to be main focus of OS
Haiku and Serenity are outright worse than Linux, especially Haiku as it's single user only
Serenity adopted Pledge and Unveil from OpenBSD but otherwise lacks basic security features
All new security paradigms seems to be happening in microkernels and these are the ones that caught my eyes
None of these are ready to be used as daily driver OS but in future (hopefully) it may change
Genode seems to be far ahead of game than everything else
Atmosphere And Mesosphere Open Source Re-implementation of Nintendo Switch's Horizon OS, I didn't expected this to be security-oriented but seems like Nintendo has done a very solid job
Of course Android is not just that and I never claimed that. Are we talking about the security of the kernel or the whole OS? If you deem the kernel used in GrapheneOS to be sufficient for you, I'm assuming that it is the rest of the OS that concerns you. What in particular do you find to be good in GrapheneOS that SELinux with AppArmor and a trusted userland doesn't achieve?
IDK why people are downvoting you, you're absolutely right.
Android is Linux (with SELinux enabled and integrated) + a userspace designed to run sandboxed applications securely. The result is much more secure than probably any Linux distro (other than stuff like Qubes).
Sandboxes employed by Flatpak and Snap are extremely weak in comparison.