A factor which might affect it: the diffraction is so huge on these tiny sensors and the cheap lenses may not be sharp, so it might be the case the image is not sharp enough for you to see the chromatic aberration! Chromatic aberration can be only seen if the image is otherwise sharp.
I'm far from certain this is the only reason for that (it might be the case that whatever little chromatic aberration there is that exceeds the diffraction and other sources of non-sharpness is removed by sophisticated algorithms processing the raw data from the sensor). But it can be a reason.
I think the combination of lack of sharpness otherwise due to diffraction / poor non-sharp lens and algorithms might explain all of what you're seeing.
Edit: @DeltaOscarUniform calculated that unless the megapixel count is excessive, the diffraction should be nonexistent due to the relatively small F-number of F2.8 (typical). Yet, the other sources of lack of sharpness prevail. However, a 12 megapixel phone camera still has half of the pixels of a 24 megapixel DSLR/mirrorless, so the low megapixel could could be (part of) an explanation.