I would count it as a high reach. Penn’s acceptance rate is small and 85% of admitted students have a 3.75 or higher (average 3.9). Students on the low end tend to be athletes, legacies, etc.
ECs can be important, but they won’t cause grades to be disregarded. There’s always a chance, admissions is not an exact science and something in your activities, essays, etc., might be especially attractive. But as a generalization, it’s a reach.