in case you didnt read early chapter, dude cant fight at all, he suck and newbie to game concept, while he cant fight but he can greatly support party, info them of enemy's position etc, and he have his tamed monster to fight as wellIf those other adventurers have any decency, they will at least pay something for the food.
Also, seriously, why doesn't the big bro try to fight? How much of a wussy can he be? It's a fricking game, yet he doesn't even try. Considering he can cook a wide variety of dishes and make clothes in the real world, he can't possibly have a mentality adverse to trying new things.