What gull wings traded in lift and drag

Did gull wings necessarily harm aircraft performance?

No. They added both lift and drag, so the result depended on the whole design and mission.

A viewer asks whether gull wings imposed a negative performance penalty. They could add both lift and resistance. The net effect depended on how the designer used the shape rather than being automatically positive or negative. For outright speed, a thin and light wing around a powerful engine remained the more direct route.