Kurt gets kicked out for being worthless at combat, then immediately becomes the most useful person in the party by doing literally everything else. The joke lands because he's genuinely better at every non-combat skill, and the show commits to it, no secret power-up, no combat revelation, just a kid who is fundamentally built different for logistics. The real party was the crafted weapons, cooked meals, and magical tools he made along the way.

Kind-hearted 15-year-old Kurt Rockhans is happy serving as the helper for the famous party Flaming Dragon Fang, until the others kick him out as useless and bring in a stronger ally. His aptitude for weapons, magic and every other combat skill sits at the lowest rank, so he takes whatever odd jobs he can find, from repairing castle walls to digging for minerals. His work quickly shows that he is anything but ordinary: in cooking, building, mining, crafting magical tools and every other non-combat field, his aptitude is SSS rank. An adventurer named Yulishia, once employed by the royal family, notices his skill, and a court official has her offer him a high status in the kingdom. Kurt waves it away, unwilling to see himself as above anyone, and keeps working, never realizing that his efforts are helping people, the town and even the country.