They are stupid. Even a cook is essential in helping them, even if from behind the scenes. Even more so when/if they need replenishment or healing. Food is as important as other magic... imagine if the cook imbues his magic in it & whatnot.
Reading enough Isekai with good cooks as the MC has me hating every single entities that reject them for their 'lowly job title'.
Ah you know what? A cook is the topmost, apex predator if you look at it from their own POV. THEY COOK OTHER LESSER BEINGS FOR THEMSELVES & OTHER HUMANS. No matter what animals or plants, if they're edible, a cook can use them all for food! Isn't that terrifying enough for you warmonger folks? Huh? No beings can escape a cook if you're food materials to them!!!
Edit: Wtf that instant leveling up had me reeling with astonishment. That monster cat's a high-level monster lol. That's right. He, as a cook, is the topmost apex predator no one ever anticipates! Don't piss off your local cook as well! You never know if they're actually a hero hunter that kills monsters for food X"D