And I am saying Oda didn’t have to keep them engaged. Where was Jinbei after beating Who's Who? Where was Denjiro for the majority of the war? Oda could have come up with much better plot structure if not for Yamato.
And I definitely do not like the character. But if anybody says Oda needed Yamato to keep the plot going, then that somebody is a crazy person. He is a writer, a story can be written in many ways. He chose to do it through Yamato, but he never managed to convince me (and hopefully many others) that Yamato was the one that needed to exist for those plot points. Instead, he had to make other characters sit down and do nothing.