I read a great book, "Designing Your Life" by Bill Burnett and Dave Evans, that said "A problem you can't change isn't a problem, it's a truth and you have to accept it". I think that mental reframing helps process effectively immutable events.
In life, society and politics, most things aren’t strictly immutable or mutable in a binary way though. What may be impossible for a single person to change, may still be subject to collective action - and collective action arises from the cumulative pressures, tensions and frustrations of many individuals. If all those individuals avoid information that could evoke these pressures, that collective action will never come into existence.
That does not seem to account for most political and social issues that you can't do much for alone, but millions of people together can bring positive change with little individual effort.