This is not a Yamao hate post. I think if Oda wanted to write Yamao's character more seriously, there are things that should be changed:
1. Instead of another pointless of "Ace is great character" wank, Oda should have made Yamao befriended Jack, and not Ace in the past.
They both are from same age, they should be childhood friends. The boy who Kaido saved in the past, and Kaido's own child.
Both were close friends, until the day Oden was executed. Then Yamao began to change (like how she is in the manga) then Jack, her closest friend, noticed it. In Jack's PoV, he started to question: why is his hero's own child began to rebel so much against her dad and their own crew, and sided with the enemy?
Their friendship started to fall apart. Without Yamao around him, and with Beast Pirates' influence, Jack also slowly began to change. From the good natured kid whom Yamao befriended, into the brutal Jack we saw in Zou.
Then in this raid, Yamao's main match should be against Jack.
"But but Jack destroyed Zou, the dukes should take care of him" yeah no. Inuarashi can try, but he loses easily because of being crippled. Inuarashi might have trump card in Sulong but Jack also should have trump card in hybrid form that he didn't use in Zou. In the end, Inuarashi lost and Yamao came to save the day.
So we could have: Zoro vs King, Sanji vs Queen, nerfed land Jinbe stomped Whos Who the strongest F6, and then Yamao vs Jack.
P.s.
Ace already bonded with Tama as Wano representative. Why should Yamao be made to bond with him too? It is not like Ace ever mentioned Yamao during his life.
2. Point taken from a fanfict I read last year: There should be more interaction between Yamao and Shogun Orochi.
Orochi, being the big womanizer man he is, should try to hit on Yamao (who is good looking) behind Kaido's knowing. Only to be intimidated by her CoC or her stare, and after that Orochi is scared to Yamao.
3. She should have helped Brook to defend Robin from CP0. Instead of making CP0 fighting pointless, filler like battle against Apoo and Drake. Oda should have turned it into 3 vs 3 match: 3 people who weren't there yet during Ennies Lobby arc: Brook, Jinbe, and Yamao vs either 3 Masked CP0 or Lucci-Kaku-Stussy trio.