No. Japanese has a LOT of homonyms. Kanji are necessary to tell the difference between all the possible meanings of a given set of sounds^. IANAL^^ but from my experience it seems Japanese is much better for speaking and reading than it is for writing. In speech the homonyms are more useful because it's easier to tell what something means from context. I find that I'm often much terser in Japanese than in English in speaking and vice-versa in writing.

^The number of kanji in use is actually INCREASING because of auto-completion software.

^^(I Am Not A Linguist), actually readability of Japanese could go either way, I'm not sure. On the one hand, the characters are more complex, requiring more space and processing; on the other, they stand for larger chunks of meaning. Has anybody here seen any studies on the reading-comprehension speed of Japanese vs. English?

^^^Also, on readability: Kanji help show the grammatical structure of a sentence somewhat. The same way you read English words by recognizing their shape, you can recognize the structure of a Japanese sentence by it's shape.