Of famous people, probably the one in my lifetime I admire most is Nelson Mandela. He was an imperfect human being, but he wrought great change and rejected chances to stay president for life when he probably could have... and although I think he might have done a better job of those who came right after him, I think the example he set made it harder for S.A. to become the next Zimbabwe.
Not really that impressed by much in the celebrity culture, but Colin Kaepernick kneeling respectfully to express his concerns regarding the real dangers many face due to racism, put his money where his mouth was and I do respect that. I am not a football fan, but I think it is sad that people protest him, but do not protest when NFL players beat up their women, commit crimes of various degrees of ugliness, and generally behave like morons. But THAT is celebrity culture. Sad that people who've hurt both other humans and animals get a pass, but he loses his career.
I'm not of the opinion that celebrities should be apolitical (or should avoid controversial opinions of any kind) or that they should just 'shut up and play/dance/sing' -- they did NOT give up their human or citizen cards when they became famous. However, I don't believe their opinions count more than anyone else's unless they actually have genuine expertise in a particular subject area. In practical terms, it also is rare that their actions amount to much.