Here’s why students with lower GPAs got in, but you didn’t: admissions is a 2 part process. First the academics, and once you qualify academically (above the bottom 25% of last year’s acceptances is a good estimate to go off of) you will be considered equally with all the other students, even with lower GPAs and test scores as long as they were above that bottom 25%. The determining factor at that point is the fit for the university. And those details needed to come out in your activity sheet and essays. If your details didn’t convey 100% of what you actually did to contribute value, the admissions officers would never know it happened.
You could try appealing if the schools you applied to accept appeals.