It is better to just let it go.
Jack's feats was great in terms of overall powerscaling. He just suffered from off-paneling and since he mostly scales to the Mink's kings featwise, many circular logic is created to downplay him
If we look at the overall manga perspective
> The Zou minks warriors were mentioned to be one of the strongest warrior countries in the new world with even Oden hyping their strength in the decisive battle against Kaido
> Sulong Carrot / Wanda were mentioned to be capable to defeat Perospero(who was lucky weather was in his favor)
> Carrot / Wanda were just one of the countless musketeers, with Carrot being a musketeer in training
> Portrayed inferior to the 3 musketeers / guardians(including BB and Giovani)
> Yet Jack overwhelmed an army of Sulong Carrot / Wanda alongside musketeer / guardians(BB, Giovani, etc) even above that in his zoan form
> And Inuarashi / Nekomamushi are the mink's kings, who not only Jack could outlast multiple times when they were switching to try to exhaust him every 12hours
> The moment Luffy saw Nekomamushi on Zou, he felt he was incredibly strong, with Sanji feeling incredible power and Capone(a SN) shivering infront of an injured Nekomamushi
> But he had to fight both Inuarashi and Nekomamushi in their sulong forms just after exhausting himself fighting a country of mink warriors in their once in a time sulong forms, with even Kaido pointing out the fact that it's not that Jack is weak for ultimately losing to them, but just the sulong kings who are that strong
And this is a Kaido who saw them fight with Jack losing, so knew exactly how strong they were. And as a comparative example, Kaido concluded that someone like Doffy must be weak for losing to Dressrosa SN after experiencing a battle against another SN portrayed on comparable level(Kid with Killer)
Of course, injured Jack ended up losing to injured Sulong Inuarashi later, but looking at how much he went through in the arc, it makes sense