There is, of course, no way to answer this objectively. It is a matter of opinion. I will provide an argument for each side of the issue so that you can think about which one makes more sense to you.
On the one hand, we can argue that the Black Panthers were an asset to social change. We can say this largely because they helped to infuse black communities with a sense of purpose and of pride. They helped to promote the idea of black nationalism which helped to make African Americans prouder of their race and less inclined to be deferential to whites. The Black Panthers, we can argue, also made the public much more aware of the issue of police brutality in African American communities. This helped lead to changes which are still ongoing today; changes which are meant to improve relations between black communities and police departments.
On the other hand, we can argue that the Black Panthers were an obstacle to social change. In this view, they unnecessarily drove wedges between the white and black community. We can argue that the Panthers were too radical and too extreme. They intentionally acted in ways that would alarm white people. This made whites, even those who were inclined to be moderate on racial issues, less likely to support the cause of black rights. We can argue that the confrontational style of the Panthers worked to break up the sort of black-white coalition that Martin Luther King, Jr.’s conciliatory style had created.
Either of these is a plausible argument. Which of them seems more credible to you?