My impression is that the GPU power consumption actually trends slightly lower on the Samsung A9s, not merely not as bad as the peak CPU power consumption. It'd be nice to see someone do tests that are even a fraction as thorough as your Android ones have been... Would AT do tests if someone donated the iPhone or money for one?
Different dynamic vs static curves (or similar metrics) would explain it; Samsung 14LPE could be better optimized for lower power than TSMC 16FF+. But I wouldn't expect LPP to sacrifice anything, so if it closes the gap at higher clocks it should still have some additional advantage at lower clocks, even if it's not as high.