These statements always bug me.
No the manga isn't better. You might think it is better but that just means you like manga.
Know why it isn't better?
It doesn't have animation, voice acting, music, or anything else an anime adds.
The manga is good, the anime is also good, they are both good.
The manga is probably longer, and more detailed, and has more character development, and so on.
Guess why? Because making a manga is cheap. So cheap in fact that it might as well be free.
The written version of anything will always be longer, have more content, more detail, more character development, etc.
The video version will have voice acting, music, animation, etc.
They are completely different forms of art, and you cannot compare the two in any meaningful way.
/EndofRant