GrapheneOS seems to be consistently the hardest to exploit AFU based on various Cellubrite leaks. iPhones have better protection than all other Androids except Pixels.
It might have to do with e.g. Apple having rolled out MIE at a broader scale than Google rolling out MTE on PixelOS, where AFAIK it is still largely opt-in (not 100% sure, I always wipe a Pixel immediately).
That's impressive!!