Maybe you say it because Zabuza was one of the first characters we saw appear, but that doesn't mean he has a low level of power, Zabuza gave Kakashi more fight than Kakuzu, who if he didn't have more lives than a cat would have died later of a single chidori, I agree that he appeared at the right time, but I think that he wasted the character's potential because we never saw his background, why he deserted, nor did we know who the other 6 swordsmen of the mist were when he belonged to said cluster.
I totally agree that Zabuza with Akatsuki as a central theme had no place in the story, but it would have been nice to see a little more about this group, rather than seeing them bite the dust as resurrected.
Thank you for sharing your opinion and commenting.