I was excited for fuchsia os but it got cancelled for phones, but then I read about HarmonyOS next which is based on OpenHarmony. which made me excited about any active forks of OpenHarmony which make it the perfect system in terms of privacy and security.
Is there is any?
Edit 1: Till now I found oniro, but I don't know if they plan on releasing any actual fork for phones or not.
To be perfectly honest, I think your best bet is to learn a programming language, get a few programmer friends together, make an account on Codeberg, and do it yourself.
Of course, there's always a chance that some fuchsia-based OS will become available for phones, but I think most people are focusing on Android ROMs and Linux phones at the moment.