First, let me say that Daniel is a truly gifted security focused developer, and that I have used GrapheneOS before - it’s excellent for security, however, it is still android. His ever improving hardened malloc implementation is also very nice.
That said, if I were to build android for my L5, I’d use GrapheneOS.
The real issue here is that he seems triggered for some reason by semantics when he fails to see the L5’s potential, even for his own project. Google etc don’t ship firmware source for their phone SoC and basebands, either. At best you may get some leaked source code for them.
The component level firmware and security updates can later be added through LVFS/fwupd, if I’m not mistaken…this will bring parity with the botnet devices while also giving us the benefit of the killswitches (and real linux if you don’t build android yourself).
One also has to consider what they expect the L5 to be - another cell phone, or is it a full fledged linux machine that is also able to make calls…I see it as the latter.