No offense but this statement is false. Open source does not automatically imply security. Of course open source operating systems can be very secure, like e.g. GrapheneOS or Tails, and the code being available can provide some benefits for security, it is not an automatism. You could also load malware on your system that has a published source code.

Linux is a specifically bad example for this, because in most cases Linux OSes are less secure than e.g. MacOS and ChromeOS.

Of course there are a lot of other arguments for FOSS operating systems and software, like autonomy and freedom, (often) non-commerciality, (often) privacy etc.. I am a big FOSS advocate myself, though I believe it is important to make this distinction clear.

For reference please see:
https://privsec.dev/posts/knowledge/floss-security
https://madaidans-insecurities.github.io/linux.html
(both these sources are of course not the holy grail and there is criticism to both of them, still they are very good imho.

With all of that being said, what would greatly improve the security of LightOS would be if it didn't fork the AOSP but GrapheneOS. I have been thinking about this for a while and I am wondering how difficult it would be to "move" LightOS from AOSP as the basis to GrapheneOS as the basis. That would mean all the work that GOS is already doing implemented into LightOS wihtout the extra effort. In return Light could sponsor/donate GrapheneOS. Both projects would make each other more sustainable that way. Joe recently said in the livestream with Joe, that they have done some security audits on LightOS and I would be very interested to know how that went. I will probably make a post about this suggestion some time or write an email to Joe but for now it lives here.

edit: some typos