It's phonetic enough to work well as one. Teaching kids to read by sounding out the words works far better than any other method (like look-say).
Have fun punishing students by making them learn 10,000 hieroglyphs instead.
With kids yes in would agree sounding out (and pointing out exceptions to the rule) works well enough. But I’m no teacher!
Unicode is about visual representation.
The argument about phonetic alphabets is they are superior to hieroglyphs.