Comment by int_19h

It plays out perfectly. E.g. Chinese is one of the least phonological scripts around, and this is precisely why old texts in it are more interpretable.

Korean Hangul is not ideographic (I think what you meant by pictorial?). It's a morphophonemic alphabet that just happens to organize the basic phonemic units into larger graphemes representing whole syllables - but in a completely predictable way. And it is another example of this playing out: the original Hangul was entirely phonemic, but over time pronunciation diverged from spelling, and today it's morpho-phonemic, and even then not perfectly so. So they preserved the history at the cost of some mismatch between the spelling and the sound.