No need to cry about it mate. Nobody is denying that Kaido and Big Mom will be destroyed for the sake of the main characters plot armour, but I at least expected Jinbe to be injured. At least missing an eye or a limb, but Oda isn't a fan of mutilation I guess. It could've added an extra layer to Luffy's desire of taking Big Mom down, but no, Oda chooses to destroy BM's portrayal instead. It makes no sense, he can give the Straw Hat's plot armour in a better, more plausible way. At this point it's clear. Every villain in the series, barring Blackbeard and perhaps Akainu, will be downplayed by Oda if they face the main protags.