You need some way to associate characters and words and to remember that association. In Chinese languages and languages that heavily borrowed Chinese vocabulary, there are at least some cues that make remembering the pronunciation easier. (Characters that share the same phonetic component are pronounced similarly.) Without those cues, using Chinese characters gets very tedious (e.g. writing native Japanese vocabulary using kanji).

If you think otherwise, why don't you try writing the English text of your comment with Chinese characters?