Why did the ancient egyptians use hieroglyphics?

Answer 1

It is very difficult to develop a writing system. At the time the Ancient Egyptians first used writing, nobody had thought of giving one symbol to each sound in the alphabet. They thought they needed a different symbol for each word. When that became too complicated, they used a combination of word-symbols and sound-symbols.

Their way of writing looks unnecessarily complicated to us, but it was an advanced and practical system under the circumstances. English is also an unnecessarily complicated writing system. We have 43 sounds represented by only 26 letters, and we don't even allocate those sounds consistently!