Being a mangaka—a Japanese comic artist—is a prestige. But the competition is tough and the crowd is hard to please. In the last decade, the number of aspiring mangaka has grown exponentially. The number of anime aired each season has doubled. Yet, one will argue that the number of quality manga stayed relatively the same.
To be blunt, I find that some of the best manga are the ones that is written not by the comic artist. But rather the ones which was written by someone else; ones that was penned by a story writer and adapted to a graphic novel by a mangaka. Consider the likes of One Punch Man and Death Note. Both are collaboration works and both are among the greatest manga ever published.