Operation System on Fairphone

I'd like to get a Fairphone without android installed, and I read about Murena OS. Everything seemed perfect until I read around that, in terms of security, there might be some issues. In the end I stumbled on this website (https://eylenburg.github.io/android\_comparison.htm) and noticed that GrapheneOS is the best OS for both privacy and security, but the only way to get it, is to buy a Google Pixel. So, in the end, I don't know what to do.

What would you recommend me?